Ambadkar P M, Killedar S J, Raval A P
Department of Zoology, M.S. University of Baroda, India.
Indian J Exp Biol. 1994 Feb;32(2):89-91.
Titres of oestrogen are known to rise from dioestrous to proestrous stage of the oestrous cycle. Such a rising level of estrogen may be responsible for rise in intracellular concentration of cAMP. The estrogen primed tissue, changing from proestrous to oestrous, under known increasing progesterone level and preovulatory LH surge, may led to a sort of balancing action on the varying levels of glycogen synthetase and phosphorylase enzyme activities so as to play a role in maintaining a steady state of glycogen concentration in the salivary gland. Therefore, alterations in glycogen concentration and the activities of concerned enzymes viz. glycogen synthetase, phosphorylase and cAMP-specific phosphodiesterase (cAMP-PDE) have been studied in albino rats. An abrupt but significant drop in cAMP-specific phosphodiesterase (cAMP-PDE) activity was found to facilitate corresponding reduction in glycogen and lowering protein concentration of the gland, during transition from oestrous to metoestrous. Main features of the meteostrous stage were depletion of glycogen and protein concentration. Taking into consideration the alteration of glandular glycogen and protein concentration, during various stages of oestrous cycle, variation in the viscosity of saliva has been suggested; in phase with the cyclicity.
已知雌激素水平在发情周期的间情期到动情前期会升高。雌激素水平的这种升高可能是细胞内cAMP浓度升高的原因。在已知孕酮水平升高和排卵前促黄体生成素激增的情况下，从动情前期转变为动情期的雌激素预处理组织，可能会对糖原合成酶和磷酸化酶活性的不同水平产生一种平衡作用，从而在维持唾液腺中糖原浓度的稳定状态方面发挥作用。因此，对白化大鼠的糖原浓度以及相关酶（即糖原合成酶、磷酸化酶和cAMP特异性磷酸二酯酶（cAMP-PDE））的活性变化进行了研究。发现在从动情期过渡到间情期时，cAMP特异性磷酸二酯酶（cAMP-PDE）活性突然但显著下降，这有助于腺体中糖原相应减少以及蛋白质浓度降低。间情期的主要特征是糖原和蛋白质浓度降低。考虑到发情周期不同阶段腺体糖原和蛋白质浓度的变化，有人提出唾液粘度会有变化，与周期同步。
