THE JOURNAL OF EXPERIMENTAL ZOOLOGY 240:363-367 (1986) Hypocalcemic Effects of Bovine Parathyroid Hormone (1-34) and Stannius Corpuscle Homogenates in Teleost Fish Adapted to Low-Calcium Water

نویسندگان

  • S. E. WENDELAAR BONGA
  • R. K. PANG
چکیده

Injections of bovine parathyroid hormone (PTH 1-34) and ho­ mogenates of corpuscles of Stannius produce hypocalcemia in male killifish and tilapia adapted to calcium-deficient seawater or fresh water, respectively. In fish from water with normal calcium concentrations no effects are noticea­ ble. These results suggest similarity in bioactivity between PTH, the hypercalcemic hormone of terrestrial vertebrates, and the hypocalcemic factor of the corpuscles of Stannius in teleost fish. Typical parathyroid glands (PT) have not been described for fish and seem to be con­ fined to the terrestrial vertebrates (Pang, '73; Roth and Schiller, '76). It has been suggested that the corpuscles of Stannius (CS), small endocrine glands in the kidneys of holostean and teleostean fish, are homologous with the PT glands (Milet et al, '79a '80; Lopez et al., '84). This suggestion was mainly based on the immunological resemblance and similar­ ities in bioactivity of parathyroid hormone (PTH) and substances present in the CS. Al­ though true homology between PT and CS has been questioned (Orimo et al., '82; Wendelaar Bonga and Pang, '86), there are un­ deniably striking similarities between the effects of PTH and CS homogenates. Milet et al. (’79a) have reported that CS homogenates increase calcium release from rat tibial bone in vitro, similar to PTH. Recently, we have confirmed this observation for mouse calvaria in vitro. We have further shown that in this preparation CS extracts have a com­ parable action to PTH on phosphate release and lactate production (Lafeber et al., ’84, ’86). With respect to the effects on blood calcium concentrations, comparison of PTH and CS homogenates has produced confusing results. In mammals, birds, reptiles, and most am­ phibians, PTH is generally considered a po­ tent hypercalcemic hormone (Dacke and Kenny, ’73; Pang et al., ’80; Sasayama and Oguro, ’82). Reports on the effects of CS ex­ tracts on plasma calcium levels in tetrapods are conflicting: hypercalcemic as well as hypocalcemic actions have been reported for rats (Leung and Fenwick, ’78; Milet et al., ’79a). CS homogenates induced hypocal­ cemia in birds (Srivastav and Swarup, ’82), whereas for amphibians hypocalcemia (Pandey et al., ’82; Milet et al., ’84) as well as hypercalcemia have been reported (Milet et al., ’84). In teleost fish, the hypocalcemic function of the CS has been well established (Fenwick, ’82). However, the effects of PTH in fish are not clear. Increased (Fleming and Meier, ’61a) as well as decreased calcium levels (Clark and Fleming, ’63; Milet et al., ’85) have been reported after PTH treatment of fish. In these experiments, the fish had been made hyper­ calcemic before injection by estrogen or by removal of the CS, and thus the effects were antihypercalcemic rather than hypocalce­ mic. In intact fish with normal calcium levels no effects of PTH could be found (Fleming and Meier, ’61b; Moss, ’63; Pang, ’73). This is not surprising since CS extracts also appear to have no substantial effect on plasma cal­ cium when injected into intact fish main­ tained in water with calcium levels in the normal range (Pang et al., ’73; Fenwick, ’82). In contrast, significant hypocalcemia could be induced by CS extracts in killifish from calcium-deficient seawater (Pang et al., ’74). In this study, the authors assumed that fish from calcium-deficient water have low circu­ lating levels of endogenous hormones and are therefore more responsive to exogenous hypocalcemic factors. In the present paper we therefore compared the effects of syn­ © 1986 ALAN R. LISS, INC. 364 S.E. WENDELAAR BONGA, R.K. PANG, AND P.K.T. PANG thetic bovine PTH (1-34) and CS homogenates on plasma calcium levels in two species of teleost fish adapted to low-calcium water. MATERIALS AND METHODS

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Hypocalcemic effects of bovine parathyroid hormone (1-34) and Stannius corpuscle homogenates in teleost fish adapted to low-calcium water.

Injections of bovine parathyroid hormone (PTH 1-34) and homogenates of corpuscles of Stannius produce hypocalcemia in male killifish and tilapia adapted to calcium-deficient seawater or fresh water, respectively. In fish from water with normal calcium concentrations no effects are noticeable. These results suggest similarity in bioactivity between PTH, the hypercalcemic hormone of terrestrial v...

متن کامل

Parathyroid hormone-like effects of rainbow trout Stannius products on bone resorption of embryonic mouse calvaria in vitro.

Products of the Stannius corpuscles (SC) of rainbow trout were tested in an established PTH bioassay involving bone resorption in embryonic mouse calvaria. Aqueous extracts from Stannius corpuscles (SC-homogenate) showed a bone-resorbing activity comparable to PTH in 24-h cultures of calvaria, indicated by a dose-dependent stimulation of lactate production and of calcium, phosphate as well as b...

متن کامل

Alterations in the Corpuscles of Stannius of Euphorbia royleana Treated Catfish, Heteropneustes fossilis

Background: We aimed to evaluate effect of Euphorbia royleana exposure on histocytology of corpuscles of Stannius in fish, Heteropneustes fossilis. Methods: Fish were subjected to 2.47 mg/L and 0.618 mg/L of E. royleana for short-term and long-term exposure, respectively. Blood samples were collected on 24, 48, 72 and 96 h in short-term and after 7, 14, 21, and 28 d in long-term experiment a...

متن کامل

Effects of lead nitrate on histo-cytological alterations of corpuscles of Stannius of stinging catfish, Heteropneustes fossilis

Background: The present study investigated the effects of lead nitrate on the histo-cytological changes in the corpuscles of Stannius (CS) of Heteropneustes fossilis. Methods: Catfish, Heteropneustes fossilis were subjected to 657.6 mg/L and 164.4 mg/L of lead nitrate for 96 h and 28 days, respectively. Blood from fish was collected on 24, 48, 72 and 96 h in short-term and after 7, 14, 21, an...

متن کامل

Transcriptomic responses of corpuscle of Stannius gland of Japanese eels (Anguilla japonica) to Changes in Water Salinity

Physiological studies of a unique endocrine gland in fish, named corpuscles of Stannius (CS), described a Ca2(+)-regulatory function for this gland mediated by stanniocalcin-1, a hypocalcemic polypeptide hormone. However, to date, the endocrine functions of the glands have not been completely elucidated.We hypothesized that other unidentified active principles in the glands are involved in the ...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2017