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The relationship between the ovary and the corpuscles of Stannius of the catfish Ompok bimaculatus (Bloch)
GENERAL
AND
COMPARATIVE
69,467-470 (1988)
ENDOCRINOLOGY
The Relationship between the Ovary and the Corpuscles of Stanni of the Catfish Ompok bimacutatus (Btoch) AMARESHCHANDRAPANDEY North-Eastern
Hill
University
Mizoram
Campus,
Pachhunga
Aizawl-796 001, Mizoram,
University India
College,
Department
of Zoology,
Accepted September 22, 1987 The corpuscles of Stannius (CS) of Ompok bimaculatus showed signs of inactivation as revealed by a significant decrease in cellular and nuclear diameters (P < 0.001) 10 days after ovariectomy. This was accompanied by accumulation of aldehyde fuchsine-positive granules in the cytoplasm. Estradiol injection partially restored the normal secretory activity of the CS cells. Estradiol administration to unoperated normal fish led to hyperactivity of the CS cells including increased cellular and nuclear diameters (P < 0.001) and depletion of granules from the cytoplasm. 0 1988 AC&& PESS, 1~. man; fish were collected during the resting stage of their ovaries (November-December). The fish were then acclimated to laboratory conditions for about 2 weeks before initiating the experiments. They were kept in glass aquaria with well-aerated running water in a room exposed to natural light and temperature and were fed on minced goat liver every alternate day throughout the period. Animals were divided into five groups: Group A: Sham-operated controls. Group B: Ovariectomized fish. Gvariectomy was performed following the procedure of Pandey (1984). Group C: Ovariectomized + estradiol (100 &day for 10 days) injected fish. Injections were started on the day of operation. Group D: Sham-injected controls receiving o&y vehicle (olive oil). Group E: Estradiol(100 Kg/day for 10 days) injected fish. Fish were killed by decapitation on the 11th day of the experiment, and the CS were fixed i.n aqueous Bouin’s fluid. Tissue blocks were then rinsed thoroughly in tap water, dehydrated in an ascending series of ethanol, cleared in xylene, and embedded in paraffin wax. Tissues were sectioned at 4-5 u.rn thickness, and serial sections were stained with hematoxyhneosin and aldehyde fuchsine (AF). The cellular and nuclear diameters, at least 1OOi CSKsh (minimum 200 numbers/fish) in each group, were measured using an ocular micrometer and the average values were determined. Statistical differences were assessed with Student’s t test.
The corpuscles of Stannius (CS) which occur uniquely in two groups of bony fishes, Holostei and Teleostei, are putative endocrine organs associated with the kidney. The information regarding their role is still enigmatic; however, several functions have been attributed to them by different workers (Pang, 1973; Krishnamurthy, 1976). Most research has dealt with the role played by the CS in osmoregulation and calcium metabolism (see Pang, 1973; Aida et al., 1980a, b; Pandey and Haider, 1982; Lopez et al., 1984). A few studies have implied some relationships between the gonads and the CS (Fontaine and Hatey, 1955; Olivereau, 1961; CCdard and Fontaine, 1963; Lopez, 1969; Heyl, 1970; Subhedar and Prasad Rao, 1979). However, no report is yet available on the effect of gonadectomy and replacement therapy on the CS. In this study, the influence of ovariectomy and estradiol treatment on the CS of Ompok bimaculatus, an airbreathing freshwater catfish, is demonstrated. MATERIALS
AND METHODS
A total of 80 sexually mature female 0. bimaculaWS, ranging from 10 to 11 cm in body length and from 15 to 20 g in body weight, were procured from fisher-
RESULTS
The CS of 0. bimaculatus
were variously
467 0016-6480/88 $1.50 Copyright 0 1988 by Academic. Press, Inc. All rights of reproduction in any form reserved.
FIG. 1. Part of the CS of control fish showing moderate granularity in the cytoplasm . AFhematoxylin, x 1650. FIG. 2. Shows the CS cells of ovariectomized fish. Note the diminished cellular and nuclear . diameters. Note the increase in the granularity of the cytoplasm. AF-hematoxylin, X 1650. FIG. 3. Section of the CS of ovariectomized + estradiol-treated fish showing almost normal secretory conditions. AF-hematoxylin, X 1650. 468
OVARIAN-CORPUSCLES
OF STANNZUS
RELATIONSHIP
469
IN A TELEOST
one type of cells (AF + and periodic acidmodified following ovariectomy and estradiol treatment (Figs. 1-3; Table 1). The CS Schiff base - ) (Pandey , 198 1; Pandey an Haider, 1982). of the ovariectomized fish showed obvious No attempt has yet been made to study signs of inactivation as revealed by the dialminished diameters of celis and nuclei (P < the possible ovary-CS relationship, though a few earlier reports suggest aher0.001) and accumulation of AF+ granules ation of the CS with gonadal activity. The in the cytoplasm (Fig. 2). Injection of estradiol (100 pg/day for 10 days) restored the possibility of involvement of the CS in the normal secretory activity of the CS (Fig. 3); gonadal physiology derives support from no significant changes were discernible in the findings of quantitative changes in the ascorbic acid content of the CS in relation the cellular and nuclear size, and the distribution of AF + granules was comparable to to sex, gonadal maturity and spawning that of the controls (Fig. 1). On the con(Fontaine and Hatey, 1955), of ~ypertro~by trary, estradiol injection (100 pglday for 10 of CS cells in the male Anguikla a~guii~~ day) of normal unoperated fish resulted in during induced gonadal maturation (Olihyperactivity of the CS. The cellular and vereau, 1961). Lopez (1969) has reported nuclear diameters were significantly in- that the CS cells are depleted of granules creased (P < O.OOl), and the AF + granules during spawning of female Sa2~o salazr, and were depleted from the cytoplasm. The de- those of reproductively adult males appear gree of degranulation was recorded on the active. The activation in males was attribbasis of the following scheme: -I- = mod- uted to their aggressive behavior and to inerate number of granules; + + = many juries inflicted as a result. granules; - = highly degranulated (TaIn describing the changes in the CS ble 1). ing the spawning migration of S. s Hey1 (197’01 pointed out that CS cells had the most intensely stained granular cytoDISCUSSION plasm when the gonads were just beginning The histophysiology of the CS of 0. bi- to enlarge and that the CS of postspa~~i~g maculatus has already been described in fish showed striking degenerative cb detail by Pandey and Haider (1982). This Subhedar and Prasad Rao (19?93 fish has a pair of CS, each consisting of only shown that the CS of postspawning (Sept.TABLE I SUMMARYOFTHERESPONSEOFTHECORPUSCLESOP STANNKJSTO~JARIECTOMY ESTRADIOL ADMINISTRATION Group (number of fish)
Treatment
A WV B (20)
Sham-operated Ovariectomized
c (20)
Ovariectomized + estradiol Vehicle-injected controls Estradiol-injected
D (10) E (2’3 a Mean 2 SE. b NS, not significant.
Cellular diameteP (wm)
Nuclear diameter” (p,m)
6.45 2 0.43 4.90 r 0.01 (P < 0.001) 6.80 + 0.38 (Wb 6.40 + O.I3
5.60 -c 0.25 3.35 F 0.07 (P < o.oor) 5.50 +- 0.90 (JWb 5.51 + 0.30
9.35 + 0.65 (P < 0.001)
7.45 k 0.12 (P < 0.001)
AND Degree of granule (AF + ) content in the cytoplasm + fS+ + -
470
AMARESH
CHANDRA
Jan.)Heteropneustes fossilis were predominantly composedof AF - cells, indicating a state of involution and inactivity. They also reported that stimulation of the CS of this fish during preparatory stageof gonad (Feb.-April) might be relatedto gonadaldevelopment. The results of the presentstudy offer limited but significant evidence that some direct or indirect relationship exists between the ovary and the CS of 0. bimaculatus. The changesobservedin the presentinvestigation may be due to one or more of the following factors: (a) ovarian estrogenmay exert some direct control over the CS; (b) estrogen may indirectly affect the CS through changes in other endocrine gland(s); (c) estrogenmay alter the serum calcium level, which in turn could affect CS activity (see Aida et al., 1980a,b). These severalpossibilities deservefurther experimental analysis. Ovariectomy-induced hyperactivity of the adrenocortical homolog has already been reported in 0. bimaculatus by Pandey (1984)and administration of estradiol is known to increase proteinbound serum calcium level in fish (Pang, 1973;Bjornsson and Haux, 1985). ACKNOWLEDGMENTS I am grateful to Dr. S. Haider, Department of Zoology, Banaras Hindu University, Varanasi, and Shri Saingenga, the Principal, PUC, NEHU, Aizawl, for extending various facilities and encouragement. I express my deep sense of gratitude to Professor Howard A. Bern, Department of Zoology, University of California, Berkeley, for critically reading the manuscript and for valuable suggestions. My thanks are also due to Shri S. N. Upadhyaya, Research Scholar, Pharmacology Department, Institute of Medical Sciences, B. H. U., Varanasi, for his help with the photography.
REFERENCES Aida, K., Nishioka, R. S., and Bern, H. A. (198Oa). Changes in the corpuscles of Stannius of Coho salmon (Oncorhynchus kisutch) during smoltification and seawater adaptation. Gen. Camp. Endocrinol. 41, 296-304.
PANDEY
Aida, K., Nishioka, R. S., and Bern, H. A. (1980b). Degranulation of the Stannius corpuscles of Coho salmon (Oncorhynchus kisutch) in response to ionic changes in vitro. Gem Comp. Endocrinol. 41, 305-313.
Bjdmsson, B. T., and Haux, C. (1985). Distribution of calcium, magnesium and inorganic phosphate in plasma of estradiol-17S treated rainbow trout. J. Comp. Physiol. B 155, 347-352. CCdard, L., and Fontaine, M. (1963). Sur la presence de sterofdes sexuels dans les corpuscles de Stannius de Saumon atlantique (Salmo salar). C.R. Acad. Sci. Paris 253, 3095-3097. Fontaine, M., and Hatey, J. (1955). Variations likes au sexe et a la maturitt g&male de la teneur en acide ascorbique des corpuscles de Stannius du saumon adulte (Salmo salur). J. Physiol. (Paris) 47, 725730.
Heyl, H. L. (1970). Changes in the corpuscles of Stannius during the spawning journey of Atlantique salmon (Salmo salar). Gen. Comp. Endocrinol. 14,43-52.
Krishnamurthy, V. G. (1976). Cytophysiology of corpuscles of Stannius. Int. Rev. Cytol. 46, 177-249. Lopez, E. (1969). Etude histophysiologique des corpuscles des Stannius de Salmo salar au tours des diverses &apes de son cycle vital. Gen. Comp. Endocrinol. 12, 339-349. Lopez, E., Tisserand-Jochem, E.-M., Eyquem, A., Milet, C., Hillyard, C., Lallier, F., Vidal, B., and Intyre, I. M. (1984). Immunocytochemical detection in eel corpuscles of Stannius of a mammalian parathyroid-like hormone. Gen. Comp. Endocrinol. 53, 28-36. Olivereau, M. (1961). Corpuscles de Stannius et reproduction chez l’anguille male. C.R. Acad. Sci. (Paris) 253, 541-543. Pandey, A. C. (1981). Cytological changes in corpuscles of Stannius of Ompok bimaculatus (Bl.) in response to hypophysectomy. Natl. Acad. Sci. Lett. 4, 483-485. Pandey, A. C. (1984). Karyometric response of the adrenocortical tissue of a freshwater teleost Ompok bimaculatus to ovariectomy. J. Adv. Zool. 5, 123125. Pandey, A. C., and Haider, S. (1982). Histophysiological studies on the corpuscles of Stanmus of the teleost Ompok bimaculatus. Ind. J. Anim. Sci. 52, 1220-1225. Pang, P. K. T. (1973). Endocrine control of calcium metabolism in teleosts. Amer. Zool. 13, 775-792. Subhedar, N., and Prasad Rao, P. D. (1979). Seasonal changes in the corpuscles of Stannius and the gonads of the catfish, Heteropneustes fossilis. Z. Mikrosk. Anat. Forsch. 93, 74-90.
AND
COMPARATIVE
69,467-470 (1988)
ENDOCRINOLOGY
The Relationship between the Ovary and the Corpuscles of Stanni of the Catfish Ompok bimacutatus (Btoch) AMARESHCHANDRAPANDEY North-Eastern
Hill
University
Mizoram
Campus,
Pachhunga
Aizawl-796 001, Mizoram,
University India
College,
Department
of Zoology,
Accepted September 22, 1987 The corpuscles of Stannius (CS) of Ompok bimaculatus showed signs of inactivation as revealed by a significant decrease in cellular and nuclear diameters (P < 0.001) 10 days after ovariectomy. This was accompanied by accumulation of aldehyde fuchsine-positive granules in the cytoplasm. Estradiol injection partially restored the normal secretory activity of the CS cells. Estradiol administration to unoperated normal fish led to hyperactivity of the CS cells including increased cellular and nuclear diameters (P < 0.001) and depletion of granules from the cytoplasm. 0 1988 AC&& PESS, 1~. man; fish were collected during the resting stage of their ovaries (November-December). The fish were then acclimated to laboratory conditions for about 2 weeks before initiating the experiments. They were kept in glass aquaria with well-aerated running water in a room exposed to natural light and temperature and were fed on minced goat liver every alternate day throughout the period. Animals were divided into five groups: Group A: Sham-operated controls. Group B: Ovariectomized fish. Gvariectomy was performed following the procedure of Pandey (1984). Group C: Ovariectomized + estradiol (100 &day for 10 days) injected fish. Injections were started on the day of operation. Group D: Sham-injected controls receiving o&y vehicle (olive oil). Group E: Estradiol(100 Kg/day for 10 days) injected fish. Fish were killed by decapitation on the 11th day of the experiment, and the CS were fixed i.n aqueous Bouin’s fluid. Tissue blocks were then rinsed thoroughly in tap water, dehydrated in an ascending series of ethanol, cleared in xylene, and embedded in paraffin wax. Tissues were sectioned at 4-5 u.rn thickness, and serial sections were stained with hematoxyhneosin and aldehyde fuchsine (AF). The cellular and nuclear diameters, at least 1OOi CSKsh (minimum 200 numbers/fish) in each group, were measured using an ocular micrometer and the average values were determined. Statistical differences were assessed with Student’s t test.
The corpuscles of Stannius (CS) which occur uniquely in two groups of bony fishes, Holostei and Teleostei, are putative endocrine organs associated with the kidney. The information regarding their role is still enigmatic; however, several functions have been attributed to them by different workers (Pang, 1973; Krishnamurthy, 1976). Most research has dealt with the role played by the CS in osmoregulation and calcium metabolism (see Pang, 1973; Aida et al., 1980a, b; Pandey and Haider, 1982; Lopez et al., 1984). A few studies have implied some relationships between the gonads and the CS (Fontaine and Hatey, 1955; Olivereau, 1961; CCdard and Fontaine, 1963; Lopez, 1969; Heyl, 1970; Subhedar and Prasad Rao, 1979). However, no report is yet available on the effect of gonadectomy and replacement therapy on the CS. In this study, the influence of ovariectomy and estradiol treatment on the CS of Ompok bimaculatus, an airbreathing freshwater catfish, is demonstrated. MATERIALS
AND METHODS
A total of 80 sexually mature female 0. bimaculaWS, ranging from 10 to 11 cm in body length and from 15 to 20 g in body weight, were procured from fisher-
RESULTS
The CS of 0. bimaculatus
were variously
467 0016-6480/88 $1.50 Copyright 0 1988 by Academic. Press, Inc. All rights of reproduction in any form reserved.
FIG. 1. Part of the CS of control fish showing moderate granularity in the cytoplasm . AFhematoxylin, x 1650. FIG. 2. Shows the CS cells of ovariectomized fish. Note the diminished cellular and nuclear . diameters. Note the increase in the granularity of the cytoplasm. AF-hematoxylin, X 1650. FIG. 3. Section of the CS of ovariectomized + estradiol-treated fish showing almost normal secretory conditions. AF-hematoxylin, X 1650. 468
OVARIAN-CORPUSCLES
OF STANNZUS
RELATIONSHIP
469
IN A TELEOST
one type of cells (AF + and periodic acidmodified following ovariectomy and estradiol treatment (Figs. 1-3; Table 1). The CS Schiff base - ) (Pandey , 198 1; Pandey an Haider, 1982). of the ovariectomized fish showed obvious No attempt has yet been made to study signs of inactivation as revealed by the dialminished diameters of celis and nuclei (P < the possible ovary-CS relationship, though a few earlier reports suggest aher0.001) and accumulation of AF+ granules ation of the CS with gonadal activity. The in the cytoplasm (Fig. 2). Injection of estradiol (100 pg/day for 10 days) restored the possibility of involvement of the CS in the normal secretory activity of the CS (Fig. 3); gonadal physiology derives support from no significant changes were discernible in the findings of quantitative changes in the ascorbic acid content of the CS in relation the cellular and nuclear size, and the distribution of AF + granules was comparable to to sex, gonadal maturity and spawning that of the controls (Fig. 1). On the con(Fontaine and Hatey, 1955), of ~ypertro~by trary, estradiol injection (100 pglday for 10 of CS cells in the male Anguikla a~guii~~ day) of normal unoperated fish resulted in during induced gonadal maturation (Olihyperactivity of the CS. The cellular and vereau, 1961). Lopez (1969) has reported nuclear diameters were significantly in- that the CS cells are depleted of granules creased (P < O.OOl), and the AF + granules during spawning of female Sa2~o salazr, and were depleted from the cytoplasm. The de- those of reproductively adult males appear gree of degranulation was recorded on the active. The activation in males was attribbasis of the following scheme: -I- = mod- uted to their aggressive behavior and to inerate number of granules; + + = many juries inflicted as a result. granules; - = highly degranulated (TaIn describing the changes in the CS ble 1). ing the spawning migration of S. s Hey1 (197’01 pointed out that CS cells had the most intensely stained granular cytoDISCUSSION plasm when the gonads were just beginning The histophysiology of the CS of 0. bi- to enlarge and that the CS of postspa~~i~g maculatus has already been described in fish showed striking degenerative cb detail by Pandey and Haider (1982). This Subhedar and Prasad Rao (19?93 fish has a pair of CS, each consisting of only shown that the CS of postspawning (Sept.TABLE I SUMMARYOFTHERESPONSEOFTHECORPUSCLESOP STANNKJSTO~JARIECTOMY ESTRADIOL ADMINISTRATION Group (number of fish)
Treatment
A WV B (20)
Sham-operated Ovariectomized
c (20)
Ovariectomized + estradiol Vehicle-injected controls Estradiol-injected
D (10) E (2’3 a Mean 2 SE. b NS, not significant.
Cellular diameteP (wm)
Nuclear diameter” (p,m)
6.45 2 0.43 4.90 r 0.01 (P < 0.001) 6.80 + 0.38 (Wb 6.40 + O.I3
5.60 -c 0.25 3.35 F 0.07 (P < o.oor) 5.50 +- 0.90 (JWb 5.51 + 0.30
9.35 + 0.65 (P < 0.001)
7.45 k 0.12 (P < 0.001)
AND Degree of granule (AF + ) content in the cytoplasm + fS+ + -
470
AMARESH
CHANDRA
Jan.)Heteropneustes fossilis were predominantly composedof AF - cells, indicating a state of involution and inactivity. They also reported that stimulation of the CS of this fish during preparatory stageof gonad (Feb.-April) might be relatedto gonadaldevelopment. The results of the presentstudy offer limited but significant evidence that some direct or indirect relationship exists between the ovary and the CS of 0. bimaculatus. The changesobservedin the presentinvestigation may be due to one or more of the following factors: (a) ovarian estrogenmay exert some direct control over the CS; (b) estrogen may indirectly affect the CS through changes in other endocrine gland(s); (c) estrogenmay alter the serum calcium level, which in turn could affect CS activity (see Aida et al., 1980a,b). These severalpossibilities deservefurther experimental analysis. Ovariectomy-induced hyperactivity of the adrenocortical homolog has already been reported in 0. bimaculatus by Pandey (1984)and administration of estradiol is known to increase proteinbound serum calcium level in fish (Pang, 1973;Bjornsson and Haux, 1985). ACKNOWLEDGMENTS I am grateful to Dr. S. Haider, Department of Zoology, Banaras Hindu University, Varanasi, and Shri Saingenga, the Principal, PUC, NEHU, Aizawl, for extending various facilities and encouragement. I express my deep sense of gratitude to Professor Howard A. Bern, Department of Zoology, University of California, Berkeley, for critically reading the manuscript and for valuable suggestions. My thanks are also due to Shri S. N. Upadhyaya, Research Scholar, Pharmacology Department, Institute of Medical Sciences, B. H. U., Varanasi, for his help with the photography.
REFERENCES Aida, K., Nishioka, R. S., and Bern, H. A. (198Oa). Changes in the corpuscles of Stannius of Coho salmon (Oncorhynchus kisutch) during smoltification and seawater adaptation. Gen. Camp. Endocrinol. 41, 296-304.
PANDEY
Aida, K., Nishioka, R. S., and Bern, H. A. (1980b). Degranulation of the Stannius corpuscles of Coho salmon (Oncorhynchus kisutch) in response to ionic changes in vitro. Gem Comp. Endocrinol. 41, 305-313.
Bjdmsson, B. T., and Haux, C. (1985). Distribution of calcium, magnesium and inorganic phosphate in plasma of estradiol-17S treated rainbow trout. J. Comp. Physiol. B 155, 347-352. CCdard, L., and Fontaine, M. (1963). Sur la presence de sterofdes sexuels dans les corpuscles de Stannius de Saumon atlantique (Salmo salar). C.R. Acad. Sci. Paris 253, 3095-3097. Fontaine, M., and Hatey, J. (1955). Variations likes au sexe et a la maturitt g&male de la teneur en acide ascorbique des corpuscles de Stannius du saumon adulte (Salmo salur). J. Physiol. (Paris) 47, 725730.
Heyl, H. L. (1970). Changes in the corpuscles of Stannius during the spawning journey of Atlantique salmon (Salmo salar). Gen. Comp. Endocrinol. 14,43-52.
Krishnamurthy, V. G. (1976). Cytophysiology of corpuscles of Stannius. Int. Rev. Cytol. 46, 177-249. Lopez, E. (1969). Etude histophysiologique des corpuscles des Stannius de Salmo salar au tours des diverses &apes de son cycle vital. Gen. Comp. Endocrinol. 12, 339-349. Lopez, E., Tisserand-Jochem, E.-M., Eyquem, A., Milet, C., Hillyard, C., Lallier, F., Vidal, B., and Intyre, I. M. (1984). Immunocytochemical detection in eel corpuscles of Stannius of a mammalian parathyroid-like hormone. Gen. Comp. Endocrinol. 53, 28-36. Olivereau, M. (1961). Corpuscles de Stannius et reproduction chez l’anguille male. C.R. Acad. Sci. (Paris) 253, 541-543. Pandey, A. C. (1981). Cytological changes in corpuscles of Stannius of Ompok bimaculatus (Bl.) in response to hypophysectomy. Natl. Acad. Sci. Lett. 4, 483-485. Pandey, A. C. (1984). Karyometric response of the adrenocortical tissue of a freshwater teleost Ompok bimaculatus to ovariectomy. J. Adv. Zool. 5, 123125. Pandey, A. C., and Haider, S. (1982). Histophysiological studies on the corpuscles of Stanmus of the teleost Ompok bimaculatus. Ind. J. Anim. Sci. 52, 1220-1225. Pang, P. K. T. (1973). Endocrine control of calcium metabolism in teleosts. Amer. Zool. 13, 775-792. Subhedar, N., and Prasad Rao, P. D. (1979). Seasonal changes in the corpuscles of Stannius and the gonads of the catfish, Heteropneustes fossilis. Z. Mikrosk. Anat. Forsch. 93, 74-90.