- Email: [email protected]
Primary malignant pericardial sarcoma
96
Letters to the Editor
Primary malignant pericardial sarcoma Wang Zhengrong, Zhu Yun ⁎, Zhang Fuchun Department of Elder Internal Medicine, Beijing University Third Hospital, China Received 3 December 2007; received in revised form 23 March 2008; accepted 29 March 2008 Available online 15 July 2008
Abstract We describe the case of a 91-year-old man who presented with a large pericardial effusion and an intrapericardial mass. Primary malignant pericardial sarcoma was diagnosed by percutaneous pericardial tumor biopsy. The patient died of multiple organ failure three months later. We also review the epidemiology, clinical presentation, pathology and treatment of cardiac tumors. The prognosis of primary malignant pericardial sarcoma is very poor especially in old people. © 2008 Elsevier Ireland Ltd. All rights reserved. Keywords: Pericardial effusion; Malignant; Sacoma
A 91-year-old man was referred to our hospital for evaluation and treatment of pericardial effusion. Dyspnea on exertion and palpitation had been apparent 10 days prior to admission. On admission, his heart rate was 89 beats/min with irregular rhythm, his blood pressure was 120/70 mmHg with paradoxical pulse. His jugular veins were distended to a height of 7 cm above the sternal angle with severe leg pitting edema. Auscultation of the chest revealed clear lungs and no cardiac murmur. A chest radiograph showed cardiomegaly and plural effusion (Fig. 1A). An electrocardiogram (ECG) showed atrial fibrillation and low voltage (Fig. 1B). Echocardiography showed large pericardial effusion and right ventricular diastolic collapse, with normal left ventricular wall thickness and an ejection fraction of 71%.(Fig. 1C). Chest computed tomography revealed plural and pericardial effusion (Fig. 1D). After admission, a transient episode of hemodynamically unstable condition was appeared, and emergent pericardiocentesis was performed, and 970 ml of bloody opaque fluid was drained. Fluid samples were studied pathologically and cultured without positive findings for tumor cells and bacteria. No neoplasm was found from lung, digestive tract, urinary tract, and so on through computed tomography, gastroscope, magnetic resonance imaging, and abdominal ultrasonic scan etc. The patient received anti-tuberculosis chemotherapy for three weeks and the pericardial effusion was slowly increased at the first month. About one month later, a mass located at the pericardium was found by echocardiogram and grew rapidly (Fig. 2E). Percutaneous pericardial tumor biopsy was performed. The microscopic examination of the biopsy showed the tumor cells were round and oval shaped without clear boundary, endochylema was reddish. The nuclei were oval-shape, with much vacuole ⁎ Corresponding author. E-mail address: [email protected] (Z. Yun).
and pathological nuclear division. Immunohistochemical studies of the tumor demonstrated that the tumor was positive for vimentin and CD99, whereas the tumor was negative for cytokeratin (CK) (mix), Des, CD20, S-100, smooth muscle actin (SMA), CD3, CD34, calretinin, and epithelial membrane antigen (EMA) (Fig. 2F–H). Combined biopsy with echocardiogram and computed tomography, the patient was diagnosed as having malignant sarcoma that originated from the pericardium. About two months later, the patient's condition deteriorated rapidly during evaluation and he developed progressive dyspnea and echocardiography revealed massive pericardial effusion with rapid increase of the tumor size (from 3.8 × 3.2 cm to 6.4 cm × 4.3 cm in about one month) and swing of the heart within the pericardium. We diagnosed cardiac tamponade, and surgical drainage was performed, a catheter was left in the pericardial space. The patient's condition continuously deteriorated and refused further interventions including surgery and chemotherapy, and died of multiple organ failure three month later. 1. Discussion Primary cardiac and pericardium tumors are very rare, with a prevalence rate ranges from 0.001% to 0.3% in collective autopsy studies, whereas metastases to the heart are far more common than primary cardiac tumors [1–5]. About 3/4 of primary cardiac tumors are benign, of which myxoma is the most common primary cardiac tumor, while angiosarcoma is the most common primary malignant tumor [1,2]. Primary pericardial tumors are much rarer than primary cardiac tumors. Over half of them are malignant, such as mesothelioma, sarcoma, etc, which is generally regarded to have a poor prognosis and usually occur at the people around the age of 20–30. One of the largest necropsy
Letters to the Editor
97
Fig. 1. A–D figures on admission: A, chest radiograph, showing cardiomegaly without pulmonary congestion. B, electrocardiogram, showing atrial fibrillation with low voltage in limb lead. C, echocardiography, showing large pericardial effusion and right ventricular diastolic collapse, with normal left ventricular wall thickness and an ejection fraction. D, computed tomography of the chest, showing plural and pericardial effusion without lung neoplasm.
series gave an incidence of primary pericardial tumors of 0.0022%, of which mesothelioma is the most common type. Benign pericardial tumors include lipoma, lobulated fibrous polyp, angieioma and dermoid tumor, etc. Patients may present with signs of pericardial effusion, heart failure, cardiac tamponade, arrhythmia, or cardiac compression depending on the site of the tumor [6,7]. The etiology of pericardial effusion in elderly people is various. The most common causes reported in China are acute idiopathic pericarditis, heart failure, tumors (primary and secondary), and tuberculosis. Majority of pericardial malignant tumors are secondary, such as metastasis of lung cancer, lymphoma, mediastinal mass, alimentary tract cancer and breast cancer [8–10]. The case in our report is a 91 year-old man with a malignant sarcoma originating in the pericardium is extremely very rare. As reported by Schumann and Holtan
[11,12], The disease presentation was varied and the diagnosis was made late in the course of the disease. With a review of the literature, few cases had been reported in the literature, and all had dismal prognosis. Most of the patients appeared signs of dyspnea, edema, arrhythmia, hemorrhagic pericardial effusion and were followed by cardiac tamponade. And sometimes the disease presented as pericarditis. Treatment depends upon a patient's cardiovascular status, symptoms, and overall health. Resection of a discrete myocardial mass has been reported. Radiation, immunologic, and cytotoxic therapy have palliative effects at best and are unlikely to induce major responses in the myocardium. The diagnosis of pericardial malignant tumor in the early stage is very difficulty. With the disease progress, signs of heart failure, cardiac tamponade, arrhythmia, or cardiac compression depending on the site and size of the tumor will
98
Letters to the Editor
Fig. 2. E, echocardiography after 2 months later, showing a giant tumor in the pericardial space and pericardial effusion. F, biopsy of the tumor, showing diffuse infiltration of round and oval shaped cells, Immunohistochemical studies of the tumor demonstrated that the tumor was positive for vimentin (G) and CD99 (H), whereas the tumor was negative for cytokeratin (CK) (mix), Des, CD20, S-100, smooth muscle actin (SMA), CD3, CD34, Calretinin, and epithelial membrane antigen (EMA) (figures were not shown).
be appeared. With the combined of increases of pericardial fluid CEA, pathologically finding of tumor cells, computed tomography of the heart, and echocardiography, positive predictive value could be up to 83% [8,9]. Biopsy of the tumor is the definitive diagnosis. In the present case, the main symptoms and signs were large pericardial effusion and cardiac tamponade. The patient's pericardial fluid CEA was not increased and no tumor cells were found under cytologic analysis, but the patient's pericardial fluid was bloody, increased rapidly, and echocardiography was found a rapid growth mass originated from pericardium. Microscopic examination and Immunohistochemical analysis of the mass biopsy confirmed that his tumor as a kind of high malignant sacoma originated from pericardium. Primary pericardial malignant tumor usually has not symptoms and signs until it causes large pericardial effusion, infiltration peripheral tissues, or its size increases large enough
and compresses the myocardium. The disease progressed rapidly with poor prognosis and limited the accumulation of our clinical experience. After reviewing the whole diagnosis and treatment for pericardial malignant tumor, we can conclude that: (1) large, bloody like, rapidly increased pericardial effusion is the character of malignant tumor, especially failed to the treatment of anti-tuberculosis; we should look for new plasma; (2) it is very important to early diagnosis, analysis of pericardial fluid, echocardiography, computed tomography or MRI of the heart, and endoscopic investigation of the pericardial cavity should be performed as possible as we can to enhance the diagnostic sensitivity. Once the solid tumor is found, Percutaneous pericardial tumor biopsy should be taken as soon as possible. This is the most important method for the correct diagnosis; (3) for the young patient or for the patient with better physical condition, early tumorectomy with chemotherapy and/or radiotherapy can be considered. However whether
Letters to the Editor
these can prolong the patient's life is not clear. For the advanced patients with poor condition, no effective method can be performed until now otherwise palliative treatment such as pericardiocentesis, catheter drainage, alleviating cardiac tamponade and supporting therapy. Our case suggests the importance of monitoring and managing cardiac tamponade in old patient, especially with a large pericardial effusion. References [1] Yu Kun, Liu Yinglong, Wang Hongyue, et al. Epidemiological and pathological characteristics of cardiac tumors: a clinical study of 242 cases. Interact CardioVasc Thorac Surg 2007;6:636–9. [2] Song Y, Hu R, Yao Q. Pathological analysis of 268 cases of tumors in the heart and the pericardium. J Sun Yat-sen-Univ (Med Sci) 2003; vol. 24:197–201. [3] Shanmugam G. Primary cardiac sarcoma. Eur J Cardiothorac Surg 2006;29(6):925–32. [4] Reynen K. Frequency of primary tumors of heart. Am J Cardiol 1996;77(1):107–16.
99
[5] Lam KY, Dickens P, Chan AC. Tumors of the heart. A 20-year experience with a review of 12,485 consecutive autopsies. Arch Pathol Lab Med 1993;117(10):1027–31. [6] Lagrotteria DD, Tsang B, Elavathil LJ, et al. A case of primary malignant pericardial mesothelioma. Can J Cardiol Feb 2005;21(2):185–7. [7] Neragi-Miandoab S, Kim J, Vlahakes GJ. Malignant tumours of the heart: a review of tumour type, diagnosis and therapy. Clin Oncol R Coll Radiol 2007;9. [8] LU Xiao-chun, LI Shi-ying. Etiology of pericardial effusion in elderly patients: a survey. Chin J Geriatr Heart Brain Vessel Dis 2005;7(6):385–7. [9] Wen Zhang, Yan Xiaowei, Fu Xiaodong, et al. Etiological analysis of the patients with pericardial effusion to be diagnosis. Chin J Cardiovasc Med 2001;6(2):89–92. [10] Gibbs CR, Watson RD, Singh SP, et al. Management of pericardial effusion by drainage: a survey of 10 years' experience in a city centre general hospital serving a multiracial population. Postgrad Med J 2000;76(902):809–13. [11] Schumann C, Kunze M, Kochs M, et al. Pericardial synovial sarcoma mimicking pericarditis in findings of cardiac magnetic resonance imaging. Int J Cardiol Jun 12 2007;118(3):e83–4. [12] Holtan SG, Allen RD, Henkel DM, et al. Angiosarcoma of the pericardium presenting as hemorrhagic pleuropericarditis, cardiac tamponade, and thromboembolic phenomena. Int J Cardiol 2007 Jan 31;115(1):e8–9.
0167-5273/$ - see front matter © 2008 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijcard.2008.03.097
Down regulation of immuno-detectable cardiac connexin-43 in BALB/c mice following acute fasting Craig S. McLachlan a,⁎, Zakaria A. Almsherqi b , Peter Mossop c , Jinya Suzuki d , See Ting Leong b , Yuru Deng b a
Department of Medicine and Molecular Biosciences, University of Technology Sydney, Australia b Department of Physiology, National University of Singapore, Singapore c Department of Medicine and Medical Imaging, St Vincent's Hospital, Melbourne, Australia d Third Department of Internal Medicine, Fukui Medical University, Fukui 910-1193, Japan Received 13 January 2008; accepted 30 March 2008 Available online 7 July 2008
Abstract Acute starvation effects for connexin-43 protein expression, in the heart, had not been previously explored. Hence we examined acute fasting on the myocardial immuno-histochemical expression of connexin-43 in 3 groups of 8-week old female BALB/c mice. Groups consisted of control mice (n = 5), fasting for 24 h (N = 5) and 48 h (N = 3). Under light microscopy all control fed cases revealed the presence of some immuno-detectable staining for connexin-43 that is either present or weakly observed in some or all of the regions of interest, that include the cross-sectional left ventricular sub-endocardium, mid-myocardium and papillary muscle. Whereas mice that underwent 24 or 48 h of acute starvation, connexin-43 expression was either difficult to detect visually (N = 3) or was completely absent (N = 5) at 40× magnification using a light microscope. In starved mice with no membrane staining for connexin-43 we observed an increase in the intracellular accumulation of cytoplasmic connexin-43 expression. © 2008 Elsevier Ireland Ltd. All rights reserved. Keywords: Myocardium; Acute starvation; Cardiac myocyte; Connexin-43
⁎ Corresponding author. E-mail address: [email protected] (C.S. McLachlan).
In the heart myocytes are electrically coupled via connexins. The major connexin found in the mammalian heart is connexin-43. Connexin-43 is a 43 kDa protein that, together with other connexins such as connexin-40 and 45,
Letters to the Editor
Primary malignant pericardial sarcoma Wang Zhengrong, Zhu Yun ⁎, Zhang Fuchun Department of Elder Internal Medicine, Beijing University Third Hospital, China Received 3 December 2007; received in revised form 23 March 2008; accepted 29 March 2008 Available online 15 July 2008
Abstract We describe the case of a 91-year-old man who presented with a large pericardial effusion and an intrapericardial mass. Primary malignant pericardial sarcoma was diagnosed by percutaneous pericardial tumor biopsy. The patient died of multiple organ failure three months later. We also review the epidemiology, clinical presentation, pathology and treatment of cardiac tumors. The prognosis of primary malignant pericardial sarcoma is very poor especially in old people. © 2008 Elsevier Ireland Ltd. All rights reserved. Keywords: Pericardial effusion; Malignant; Sacoma
A 91-year-old man was referred to our hospital for evaluation and treatment of pericardial effusion. Dyspnea on exertion and palpitation had been apparent 10 days prior to admission. On admission, his heart rate was 89 beats/min with irregular rhythm, his blood pressure was 120/70 mmHg with paradoxical pulse. His jugular veins were distended to a height of 7 cm above the sternal angle with severe leg pitting edema. Auscultation of the chest revealed clear lungs and no cardiac murmur. A chest radiograph showed cardiomegaly and plural effusion (Fig. 1A). An electrocardiogram (ECG) showed atrial fibrillation and low voltage (Fig. 1B). Echocardiography showed large pericardial effusion and right ventricular diastolic collapse, with normal left ventricular wall thickness and an ejection fraction of 71%.(Fig. 1C). Chest computed tomography revealed plural and pericardial effusion (Fig. 1D). After admission, a transient episode of hemodynamically unstable condition was appeared, and emergent pericardiocentesis was performed, and 970 ml of bloody opaque fluid was drained. Fluid samples were studied pathologically and cultured without positive findings for tumor cells and bacteria. No neoplasm was found from lung, digestive tract, urinary tract, and so on through computed tomography, gastroscope, magnetic resonance imaging, and abdominal ultrasonic scan etc. The patient received anti-tuberculosis chemotherapy for three weeks and the pericardial effusion was slowly increased at the first month. About one month later, a mass located at the pericardium was found by echocardiogram and grew rapidly (Fig. 2E). Percutaneous pericardial tumor biopsy was performed. The microscopic examination of the biopsy showed the tumor cells were round and oval shaped without clear boundary, endochylema was reddish. The nuclei were oval-shape, with much vacuole ⁎ Corresponding author. E-mail address: [email protected] (Z. Yun).
and pathological nuclear division. Immunohistochemical studies of the tumor demonstrated that the tumor was positive for vimentin and CD99, whereas the tumor was negative for cytokeratin (CK) (mix), Des, CD20, S-100, smooth muscle actin (SMA), CD3, CD34, calretinin, and epithelial membrane antigen (EMA) (Fig. 2F–H). Combined biopsy with echocardiogram and computed tomography, the patient was diagnosed as having malignant sarcoma that originated from the pericardium. About two months later, the patient's condition deteriorated rapidly during evaluation and he developed progressive dyspnea and echocardiography revealed massive pericardial effusion with rapid increase of the tumor size (from 3.8 × 3.2 cm to 6.4 cm × 4.3 cm in about one month) and swing of the heart within the pericardium. We diagnosed cardiac tamponade, and surgical drainage was performed, a catheter was left in the pericardial space. The patient's condition continuously deteriorated and refused further interventions including surgery and chemotherapy, and died of multiple organ failure three month later. 1. Discussion Primary cardiac and pericardium tumors are very rare, with a prevalence rate ranges from 0.001% to 0.3% in collective autopsy studies, whereas metastases to the heart are far more common than primary cardiac tumors [1–5]. About 3/4 of primary cardiac tumors are benign, of which myxoma is the most common primary cardiac tumor, while angiosarcoma is the most common primary malignant tumor [1,2]. Primary pericardial tumors are much rarer than primary cardiac tumors. Over half of them are malignant, such as mesothelioma, sarcoma, etc, which is generally regarded to have a poor prognosis and usually occur at the people around the age of 20–30. One of the largest necropsy
Letters to the Editor
97
Fig. 1. A–D figures on admission: A, chest radiograph, showing cardiomegaly without pulmonary congestion. B, electrocardiogram, showing atrial fibrillation with low voltage in limb lead. C, echocardiography, showing large pericardial effusion and right ventricular diastolic collapse, with normal left ventricular wall thickness and an ejection fraction. D, computed tomography of the chest, showing plural and pericardial effusion without lung neoplasm.
series gave an incidence of primary pericardial tumors of 0.0022%, of which mesothelioma is the most common type. Benign pericardial tumors include lipoma, lobulated fibrous polyp, angieioma and dermoid tumor, etc. Patients may present with signs of pericardial effusion, heart failure, cardiac tamponade, arrhythmia, or cardiac compression depending on the site of the tumor [6,7]. The etiology of pericardial effusion in elderly people is various. The most common causes reported in China are acute idiopathic pericarditis, heart failure, tumors (primary and secondary), and tuberculosis. Majority of pericardial malignant tumors are secondary, such as metastasis of lung cancer, lymphoma, mediastinal mass, alimentary tract cancer and breast cancer [8–10]. The case in our report is a 91 year-old man with a malignant sarcoma originating in the pericardium is extremely very rare. As reported by Schumann and Holtan
[11,12], The disease presentation was varied and the diagnosis was made late in the course of the disease. With a review of the literature, few cases had been reported in the literature, and all had dismal prognosis. Most of the patients appeared signs of dyspnea, edema, arrhythmia, hemorrhagic pericardial effusion and were followed by cardiac tamponade. And sometimes the disease presented as pericarditis. Treatment depends upon a patient's cardiovascular status, symptoms, and overall health. Resection of a discrete myocardial mass has been reported. Radiation, immunologic, and cytotoxic therapy have palliative effects at best and are unlikely to induce major responses in the myocardium. The diagnosis of pericardial malignant tumor in the early stage is very difficulty. With the disease progress, signs of heart failure, cardiac tamponade, arrhythmia, or cardiac compression depending on the site and size of the tumor will
98
Letters to the Editor
Fig. 2. E, echocardiography after 2 months later, showing a giant tumor in the pericardial space and pericardial effusion. F, biopsy of the tumor, showing diffuse infiltration of round and oval shaped cells, Immunohistochemical studies of the tumor demonstrated that the tumor was positive for vimentin (G) and CD99 (H), whereas the tumor was negative for cytokeratin (CK) (mix), Des, CD20, S-100, smooth muscle actin (SMA), CD3, CD34, Calretinin, and epithelial membrane antigen (EMA) (figures were not shown).
be appeared. With the combined of increases of pericardial fluid CEA, pathologically finding of tumor cells, computed tomography of the heart, and echocardiography, positive predictive value could be up to 83% [8,9]. Biopsy of the tumor is the definitive diagnosis. In the present case, the main symptoms and signs were large pericardial effusion and cardiac tamponade. The patient's pericardial fluid CEA was not increased and no tumor cells were found under cytologic analysis, but the patient's pericardial fluid was bloody, increased rapidly, and echocardiography was found a rapid growth mass originated from pericardium. Microscopic examination and Immunohistochemical analysis of the mass biopsy confirmed that his tumor as a kind of high malignant sacoma originated from pericardium. Primary pericardial malignant tumor usually has not symptoms and signs until it causes large pericardial effusion, infiltration peripheral tissues, or its size increases large enough
and compresses the myocardium. The disease progressed rapidly with poor prognosis and limited the accumulation of our clinical experience. After reviewing the whole diagnosis and treatment for pericardial malignant tumor, we can conclude that: (1) large, bloody like, rapidly increased pericardial effusion is the character of malignant tumor, especially failed to the treatment of anti-tuberculosis; we should look for new plasma; (2) it is very important to early diagnosis, analysis of pericardial fluid, echocardiography, computed tomography or MRI of the heart, and endoscopic investigation of the pericardial cavity should be performed as possible as we can to enhance the diagnostic sensitivity. Once the solid tumor is found, Percutaneous pericardial tumor biopsy should be taken as soon as possible. This is the most important method for the correct diagnosis; (3) for the young patient or for the patient with better physical condition, early tumorectomy with chemotherapy and/or radiotherapy can be considered. However whether
Letters to the Editor
these can prolong the patient's life is not clear. For the advanced patients with poor condition, no effective method can be performed until now otherwise palliative treatment such as pericardiocentesis, catheter drainage, alleviating cardiac tamponade and supporting therapy. Our case suggests the importance of monitoring and managing cardiac tamponade in old patient, especially with a large pericardial effusion. References [1] Yu Kun, Liu Yinglong, Wang Hongyue, et al. Epidemiological and pathological characteristics of cardiac tumors: a clinical study of 242 cases. Interact CardioVasc Thorac Surg 2007;6:636–9. [2] Song Y, Hu R, Yao Q. Pathological analysis of 268 cases of tumors in the heart and the pericardium. J Sun Yat-sen-Univ (Med Sci) 2003; vol. 24:197–201. [3] Shanmugam G. Primary cardiac sarcoma. Eur J Cardiothorac Surg 2006;29(6):925–32. [4] Reynen K. Frequency of primary tumors of heart. Am J Cardiol 1996;77(1):107–16.
99
[5] Lam KY, Dickens P, Chan AC. Tumors of the heart. A 20-year experience with a review of 12,485 consecutive autopsies. Arch Pathol Lab Med 1993;117(10):1027–31. [6] Lagrotteria DD, Tsang B, Elavathil LJ, et al. A case of primary malignant pericardial mesothelioma. Can J Cardiol Feb 2005;21(2):185–7. [7] Neragi-Miandoab S, Kim J, Vlahakes GJ. Malignant tumours of the heart: a review of tumour type, diagnosis and therapy. Clin Oncol R Coll Radiol 2007;9. [8] LU Xiao-chun, LI Shi-ying. Etiology of pericardial effusion in elderly patients: a survey. Chin J Geriatr Heart Brain Vessel Dis 2005;7(6):385–7. [9] Wen Zhang, Yan Xiaowei, Fu Xiaodong, et al. Etiological analysis of the patients with pericardial effusion to be diagnosis. Chin J Cardiovasc Med 2001;6(2):89–92. [10] Gibbs CR, Watson RD, Singh SP, et al. Management of pericardial effusion by drainage: a survey of 10 years' experience in a city centre general hospital serving a multiracial population. Postgrad Med J 2000;76(902):809–13. [11] Schumann C, Kunze M, Kochs M, et al. Pericardial synovial sarcoma mimicking pericarditis in findings of cardiac magnetic resonance imaging. Int J Cardiol Jun 12 2007;118(3):e83–4. [12] Holtan SG, Allen RD, Henkel DM, et al. Angiosarcoma of the pericardium presenting as hemorrhagic pleuropericarditis, cardiac tamponade, and thromboembolic phenomena. Int J Cardiol 2007 Jan 31;115(1):e8–9.
0167-5273/$ - see front matter © 2008 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijcard.2008.03.097
Down regulation of immuno-detectable cardiac connexin-43 in BALB/c mice following acute fasting Craig S. McLachlan a,⁎, Zakaria A. Almsherqi b , Peter Mossop c , Jinya Suzuki d , See Ting Leong b , Yuru Deng b a
Department of Medicine and Molecular Biosciences, University of Technology Sydney, Australia b Department of Physiology, National University of Singapore, Singapore c Department of Medicine and Medical Imaging, St Vincent's Hospital, Melbourne, Australia d Third Department of Internal Medicine, Fukui Medical University, Fukui 910-1193, Japan Received 13 January 2008; accepted 30 March 2008 Available online 7 July 2008
Abstract Acute starvation effects for connexin-43 protein expression, in the heart, had not been previously explored. Hence we examined acute fasting on the myocardial immuno-histochemical expression of connexin-43 in 3 groups of 8-week old female BALB/c mice. Groups consisted of control mice (n = 5), fasting for 24 h (N = 5) and 48 h (N = 3). Under light microscopy all control fed cases revealed the presence of some immuno-detectable staining for connexin-43 that is either present or weakly observed in some or all of the regions of interest, that include the cross-sectional left ventricular sub-endocardium, mid-myocardium and papillary muscle. Whereas mice that underwent 24 or 48 h of acute starvation, connexin-43 expression was either difficult to detect visually (N = 3) or was completely absent (N = 5) at 40× magnification using a light microscope. In starved mice with no membrane staining for connexin-43 we observed an increase in the intracellular accumulation of cytoplasmic connexin-43 expression. © 2008 Elsevier Ireland Ltd. All rights reserved. Keywords: Myocardium; Acute starvation; Cardiac myocyte; Connexin-43
⁎ Corresponding author. E-mail address: [email protected] (C.S. McLachlan).
In the heart myocytes are electrically coupled via connexins. The major connexin found in the mammalian heart is connexin-43. Connexin-43 is a 43 kDa protein that, together with other connexins such as connexin-40 and 45,