Lu R B, Chaichanwatanakul K, Lin C H, Lebenthal E, Lee P C
Children's Hospital of Buffalo, Department of Pediatrics, State University of New York 14222.
Am J Physiol. 1988 Mar;254(3 Pt 1):G315-21. doi: 10.1152/ajpgi.1988.254.3.G315.
Thyroxine and glucocorticoids both play important roles in regulating the development of mammalian tissues. The mechanisms by which they modulate the developmental process is not fully understood. Furthermore, the interaction between the effects of two hormones on the pancreas has not been studied in detail. To investigate these issues, we studied the effect of thyroxine and/or corticosterone on the development of the exocrine pancreas in normal and adrenalectomized rats. Daily injection of thyroxine (0.1 micrograms/g body wt) to pups starting at day 5 of age resulted in precocious increases of exocrine enzymes in the pancreata of these pups. Hypothyroid pups, induced by propylthiouracil, exhibited suppression of development of their pancreatic exocrine enzymes. Replacement of thyroxine or corticosterone alleviated the suppression of exocrine enzyme development in these pups. Rat pups, who underwent adrenalectomy at 5 days of age, had undetectable plasma corticosterone and exhibited similar suppression of pancreatic enzyme development. Injection of thyroxine or corticosterone alone to adrenalectomized pups led to normal development of exocrine pancreatic enzymes. When both thyroxine and corticosterone were given together to adrenalectomized pups, their pancreatic enzyme levels were found to increase to values above those of pups treated with thyroxine or corticosterone alone. We conclude that thyroxine has both direct and indirect modulatory roles in the development of the rat exocrine pancreas. Normal development of the exocrine pancreas depends on both intact adrenal and thyroid function in the rat.
甲状腺素和糖皮质激素在调节哺乳动物组织发育过程中均发挥着重要作用。它们调节发育进程的机制尚未完全明确。此外，两种激素对胰腺影响之间的相互作用也未得到详细研究。为了探究这些问题，我们研究了甲状腺素和/或皮质酮对正常及肾上腺切除大鼠外分泌胰腺发育的影响。从出生第5天开始，每天给幼鼠注射甲状腺素（0.1微克/克体重），导致这些幼鼠胰腺中的外分泌酶过早增加。由丙硫氧嘧啶诱导的甲状腺功能减退幼鼠，其胰腺外分泌酶的发育受到抑制。补充甲状腺素或皮质酮可缓解这些幼鼠外分泌酶发育的抑制情况。5日龄接受肾上腺切除术的幼鼠，其血浆皮质酮检测不到，并且胰腺酶发育也表现出类似的抑制情况。单独给肾上腺切除的幼鼠注射甲状腺素或皮质酮，可使外分泌胰腺酶正常发育。当同时给肾上腺切除的幼鼠注射甲状腺素和皮质酮时，发现它们的胰腺酶水平升高至高于单独用甲状腺素或皮质酮处理的幼鼠。我们得出结论，甲状腺素在大鼠外分泌胰腺发育中具有直接和间接的调节作用。大鼠外分泌胰腺的正常发育依赖于完整的肾上腺和甲状腺功能。
