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Plasma atrial natriuretic peptide in normal calves during the first 10 days of life
Research in Veterinary Science 1994, 57, 251-252
Plasma atrial natriuretic peptide in normal calves during the first 10 days of life N. TAKEMURA, H. KOYAMA, T. SAKO, Department of Veterinary Internal Medicine, K. SUZUKI, Department of VeterinaryPhysiology, S. MOTOYOSHI, Department of VeterinaryInternal Medicine, Nippon Veterinaryand
Animal Science University, 1-7-1 Kyonan-eho, Musashino-shi, Tokyo 180, Japan
The concentration and molecular form of the plasma atrial natriuretic peptidc (ANP) in normal calves during the first 10 days of life were investigated. The mean (SEM) ANP concentration on the day of birth was 62"7 (5-52) pmol litre-1, and thereafter it decreased progressively and significantly (P<0.001). After 10 days, the plasma ANP concentration had decreased to normal adult values (11.3 [3"87] pmol litre-1). On the day of birth and 10 days later a single peak corresponding to cz-ANP alone was detected in the plasma of the calves.
ATRIAL natriuretic peptide (ANP)is a hormone which is released from the heart into the blood circulation by atrial distension, and which controls water and sodium balance in the body (Cantin and Genest 1985). High concentrations of ANP and high molecular weight forms of ANP, ie, 13- and ?-ANPS have been observed in the plasma of animals with heart failure due to dilated cardiomyopathy, mitral regurgitation and heartworm infection (Takemura et al 1990, 1991a, b). Although high plasma concentrations of aNp have also been observed in human neonates, little is known about the role of ANP during early life (Rascher et al 1987, Ito et al 1990). In the present study, the concentration and molecular form of ANP were investigated in calves during the first 10 days of life. Five full term Holstein calves delivered per vaginum after an uncomplicated pregnancy were used; they remained healthy during the study. Blood samples were taken from a jugular vein within six hours after birth and then after one, three, five and 10 days. The first two samples were taken with the calf in lateral recumbency, and the remainder with the calves standing. The calves received maternal milk for the first two days and then milk replacer as the main feed. The plasma samples were prepared as described by Takemura et al (1989). The concentration and molecular form of the plasma ANP were determined by radioimmunoassay and gel permeation chromatography (GPC), respectively, as described by Takemura et al (1989, 1990). Fig 1 shows the plasma ANe concentrations of the individual calves during the first 10 days. The highest concentration
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Postnatal age
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10 (days)
FIG 1: Concentrations of atrial natriuretic peptide (ANP) in the plasma of five calves during their first 10 days of life
(mean [SEM]) observed on the day of birth (62.7 [5.52] pmol litre-t) was significantly higher than the values reported for 12 normal adult cattle (14'5 [1-84] pmol litre-1, P<0.01), but not significantly different from the concentration in four cattle with severe congestive heart failure (73.3 [16'0] pmol litre-t, Takemura et al 1990) when analysed by an unpaired Student's t test. The plasma ANP concentration then decreased progressively and significantly with time (two-way ANOVA,P<0'001). The concentration observed on day 10 (11.3 [3'87] pmol litre-1) was similar to normal adult values. GrC revealed a single peak corresponding to ~-ANP in all the plasma samples taken on the day of birth and 10 days after birth. The authors have observed a significant increase in ANP concentration in animals with heart failure, which was closely related to cardiac haemodynamics (Takemura et al 1990, 1991a, b). The increased concentrations of ANP observed in the plasma and the atrial tissues of human beings (Akimoto et al 1988, Marumo et al
251
252
N. Takemura, H. Koyama, T. Sako, K. Suzuki, S. Motoyoshi
1988) and cattle (Takemura et al 1990) with heart failure, and in human neonates (Ito et al 1990) was associated with the appearance of [3- and/or T-ANP(S). However, in the present study, in spite of the increased concentration of ANP, the high molecular weight form of the molecule was not detected; this difference might be due to different mechanisms of synthesis and/or to the increased excretion of the high molecular weight form by the cardiocyte. The high concentration of ANP observed in this study may have been caused either by the increased blood return to the left atrium, due to the onset of the pulmonary circulation, or by a reduction in the uptake of ANP by the peripheral organs during the period shortly after birth (Andresen et al 1987). In human neonates, Ito et al (1990) reported that there was no relationship between the changes in plasma ANP concentration and bodyweight. However, a high plasma ANP concentration has been shown to be related to the onset of diuresis during the early post natal period (Tulassay et al 1987, Kojima et al 1987). The extracellular fluid x~olume, the time of micturition and the volume of urine passed by these calves were not measured. However, the initial high plasma concentration of ANP after birth may suggest that it plays a role in the excretion of excess body fluid in newborn calves. Another possible role for the high concentration of ANP is to dilate the peripheral arteries (Cantin and Genest 1985); ANP-induced vascular dilation, resulting in a lowering of blood pressure, could be important during the early post natal period when the blood supply to organs such as skeletal muscle, myocardium and lung must be increased significantly from that required by the fetus. Acknowledgements This work was supported in part by a grant-in-aid for Special Scientific Research on Agriculture, Forestry and Fisheries from the Ministry of Agriculture, Forestry and Fisheries in Japan.
References AKIMOTO, K., MIYATA, A., KANGAWA, K., KOGA, Y., HAYAKAWA, K. & MATSUO, H. (1988) Molecular forms of atrial natriuretic peptide in the atrium of patients with cardiovascular disease. Journal of Clinical Endocrinology and Metabolism 67, 93-97 ANDRESEN, A. A., VARILLE, V. A., NAKAMURA, K. & ROBILLARD, J. E. (1987) Effects of a c~-human atrial natriuretic polypeptide (ANP) on renal function during development. Pediatric Research 21, 47 (Abstract) CANTIN, M. & GENEST, J. (1985) The heart and the atrial natrittretie factor. Endocrine Reviews 6, 107-127
ITO, Y., MARUMO, F., ANDO, K., HAYASHI, M. & YAMASHITA, F. (1990) The physiological and biological significanees of human atrial natrinretic peptide in neonates. Acta Paediatrica Scandinavia
79, 26-31 KOJIMA, T., HIRATA, Y., FUKUDA, Y., IWASE, S. & KOBAYASHI, Y. (1987) Plasma atrial natriuretic peptide and spontaneous diuresis in sick neonates. Archives of Disease in Childhood 62, 667-670 MARUMO, F., KUROSAWA, T., TAKEDA, S., KATOH, Y., HASEGAWA, N. & ANDO, K. (1988) Changes of molecular forms of atrial natriuretic peptide after treatment for congestive heart failure. Klinisehe Wochenschrift 66, 675-681
RASCHER, W., BALD, M., KREIS, J., TULASSAY, T., HEINRICH, U. & SCHARER, K. (1987) Atrial natriuretic peptide in infants and children. Hormone Research 28, 58-63 TAKEMURA, N., KOYAMA, H., SAKO, T., ANDO, K., UCH1NO, T., MOTOYOSHI, S. & MARUMO, F. (1989) Measurement of atrial natriuretie peptide (ANP) in bovine plasma and urine. Japanese Journal of Veterinary Science 51, 843-845 TAKEMURA, N., KOYAMA, H., SAKO, T., ANDO, K., SUZUKI, K., MOTOYOSHI, S. & MARUMO, F. (1991a) Atrial natriuretic peptide in the dog with mitral regurgitation. Research in Veterinary Science 50, 86-88 TAKEMURA, N., KOYAMA, H., SAKO, T., ANDO, K., MOTOYOSHI, S. & MARUMO, F. (1990) Bovine natruretie peptide in heart failure. Journal of Endocrinology 124, 463-467 TAKEMURA, N., KOYAMA, H., SAKO, T., ANDO, K., MOTOYOSHI, S. & MARUMO, F. (1991b) Plasma atrial natriuretic peptide (ANP) in dogs with mild heartworm infection. Journal of Veterinary Medical Science 53, 323-325 TULASSAY, T., SERI, I. & RASCHER, W. (1987) Atrial natriuretic peptide and extracellular volume contraction after bi~h. Acta Paediatrica Scandinavia 76, 444-446 Received August 23, 1993 Accepted March 11, 1994
Plasma atrial natriuretic peptide in normal calves during the first 10 days of life N. TAKEMURA, H. KOYAMA, T. SAKO, Department of Veterinary Internal Medicine, K. SUZUKI, Department of VeterinaryPhysiology, S. MOTOYOSHI, Department of VeterinaryInternal Medicine, Nippon Veterinaryand
Animal Science University, 1-7-1 Kyonan-eho, Musashino-shi, Tokyo 180, Japan
The concentration and molecular form of the plasma atrial natriuretic peptidc (ANP) in normal calves during the first 10 days of life were investigated. The mean (SEM) ANP concentration on the day of birth was 62"7 (5-52) pmol litre-1, and thereafter it decreased progressively and significantly (P<0.001). After 10 days, the plasma ANP concentration had decreased to normal adult values (11.3 [3"87] pmol litre-1). On the day of birth and 10 days later a single peak corresponding to cz-ANP alone was detected in the plasma of the calves.
ATRIAL natriuretic peptide (ANP)is a hormone which is released from the heart into the blood circulation by atrial distension, and which controls water and sodium balance in the body (Cantin and Genest 1985). High concentrations of ANP and high molecular weight forms of ANP, ie, 13- and ?-ANPS have been observed in the plasma of animals with heart failure due to dilated cardiomyopathy, mitral regurgitation and heartworm infection (Takemura et al 1990, 1991a, b). Although high plasma concentrations of aNp have also been observed in human neonates, little is known about the role of ANP during early life (Rascher et al 1987, Ito et al 1990). In the present study, the concentration and molecular form of ANP were investigated in calves during the first 10 days of life. Five full term Holstein calves delivered per vaginum after an uncomplicated pregnancy were used; they remained healthy during the study. Blood samples were taken from a jugular vein within six hours after birth and then after one, three, five and 10 days. The first two samples were taken with the calf in lateral recumbency, and the remainder with the calves standing. The calves received maternal milk for the first two days and then milk replacer as the main feed. The plasma samples were prepared as described by Takemura et al (1989). The concentration and molecular form of the plasma ANP were determined by radioimmunoassay and gel permeation chromatography (GPC), respectively, as described by Takemura et al (1989, 1990). Fig 1 shows the plasma ANe concentrations of the individual calves during the first 10 days. The highest concentration
"7 "7
"6
90
.~
70
50 o
~z <
30
E
10
m
l
i
I
t~
l
0 1
l
i
3
l
II
|
5
Postnatal age
II
|
l
II
10 (days)
FIG 1: Concentrations of atrial natriuretic peptide (ANP) in the plasma of five calves during their first 10 days of life
(mean [SEM]) observed on the day of birth (62.7 [5.52] pmol litre-t) was significantly higher than the values reported for 12 normal adult cattle (14'5 [1-84] pmol litre-1, P<0.01), but not significantly different from the concentration in four cattle with severe congestive heart failure (73.3 [16'0] pmol litre-t, Takemura et al 1990) when analysed by an unpaired Student's t test. The plasma ANP concentration then decreased progressively and significantly with time (two-way ANOVA,P<0'001). The concentration observed on day 10 (11.3 [3'87] pmol litre-1) was similar to normal adult values. GrC revealed a single peak corresponding to ~-ANP in all the plasma samples taken on the day of birth and 10 days after birth. The authors have observed a significant increase in ANP concentration in animals with heart failure, which was closely related to cardiac haemodynamics (Takemura et al 1990, 1991a, b). The increased concentrations of ANP observed in the plasma and the atrial tissues of human beings (Akimoto et al 1988, Marumo et al
251
252
N. Takemura, H. Koyama, T. Sako, K. Suzuki, S. Motoyoshi
1988) and cattle (Takemura et al 1990) with heart failure, and in human neonates (Ito et al 1990) was associated with the appearance of [3- and/or T-ANP(S). However, in the present study, in spite of the increased concentration of ANP, the high molecular weight form of the molecule was not detected; this difference might be due to different mechanisms of synthesis and/or to the increased excretion of the high molecular weight form by the cardiocyte. The high concentration of ANP observed in this study may have been caused either by the increased blood return to the left atrium, due to the onset of the pulmonary circulation, or by a reduction in the uptake of ANP by the peripheral organs during the period shortly after birth (Andresen et al 1987). In human neonates, Ito et al (1990) reported that there was no relationship between the changes in plasma ANP concentration and bodyweight. However, a high plasma ANP concentration has been shown to be related to the onset of diuresis during the early post natal period (Tulassay et al 1987, Kojima et al 1987). The extracellular fluid x~olume, the time of micturition and the volume of urine passed by these calves were not measured. However, the initial high plasma concentration of ANP after birth may suggest that it plays a role in the excretion of excess body fluid in newborn calves. Another possible role for the high concentration of ANP is to dilate the peripheral arteries (Cantin and Genest 1985); ANP-induced vascular dilation, resulting in a lowering of blood pressure, could be important during the early post natal period when the blood supply to organs such as skeletal muscle, myocardium and lung must be increased significantly from that required by the fetus. Acknowledgements This work was supported in part by a grant-in-aid for Special Scientific Research on Agriculture, Forestry and Fisheries from the Ministry of Agriculture, Forestry and Fisheries in Japan.
References AKIMOTO, K., MIYATA, A., KANGAWA, K., KOGA, Y., HAYAKAWA, K. & MATSUO, H. (1988) Molecular forms of atrial natriuretic peptide in the atrium of patients with cardiovascular disease. Journal of Clinical Endocrinology and Metabolism 67, 93-97 ANDRESEN, A. A., VARILLE, V. A., NAKAMURA, K. & ROBILLARD, J. E. (1987) Effects of a c~-human atrial natriuretic polypeptide (ANP) on renal function during development. Pediatric Research 21, 47 (Abstract) CANTIN, M. & GENEST, J. (1985) The heart and the atrial natrittretie factor. Endocrine Reviews 6, 107-127
ITO, Y., MARUMO, F., ANDO, K., HAYASHI, M. & YAMASHITA, F. (1990) The physiological and biological significanees of human atrial natrinretic peptide in neonates. Acta Paediatrica Scandinavia
79, 26-31 KOJIMA, T., HIRATA, Y., FUKUDA, Y., IWASE, S. & KOBAYASHI, Y. (1987) Plasma atrial natriuretic peptide and spontaneous diuresis in sick neonates. Archives of Disease in Childhood 62, 667-670 MARUMO, F., KUROSAWA, T., TAKEDA, S., KATOH, Y., HASEGAWA, N. & ANDO, K. (1988) Changes of molecular forms of atrial natriuretic peptide after treatment for congestive heart failure. Klinisehe Wochenschrift 66, 675-681
RASCHER, W., BALD, M., KREIS, J., TULASSAY, T., HEINRICH, U. & SCHARER, K. (1987) Atrial natriuretic peptide in infants and children. Hormone Research 28, 58-63 TAKEMURA, N., KOYAMA, H., SAKO, T., ANDO, K., UCH1NO, T., MOTOYOSHI, S. & MARUMO, F. (1989) Measurement of atrial natriuretie peptide (ANP) in bovine plasma and urine. Japanese Journal of Veterinary Science 51, 843-845 TAKEMURA, N., KOYAMA, H., SAKO, T., ANDO, K., SUZUKI, K., MOTOYOSHI, S. & MARUMO, F. (1991a) Atrial natriuretic peptide in the dog with mitral regurgitation. Research in Veterinary Science 50, 86-88 TAKEMURA, N., KOYAMA, H., SAKO, T., ANDO, K., MOTOYOSHI, S. & MARUMO, F. (1990) Bovine natruretie peptide in heart failure. Journal of Endocrinology 124, 463-467 TAKEMURA, N., KOYAMA, H., SAKO, T., ANDO, K., MOTOYOSHI, S. & MARUMO, F. (1991b) Plasma atrial natriuretic peptide (ANP) in dogs with mild heartworm infection. Journal of Veterinary Medical Science 53, 323-325 TULASSAY, T., SERI, I. & RASCHER, W. (1987) Atrial natriuretic peptide and extracellular volume contraction after bi~h. Acta Paediatrica Scandinavia 76, 444-446 Received August 23, 1993 Accepted March 11, 1994