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General Comment |
Parvalbumin (PV) is a high-affinity Ca(2+)-binding protein which is expressed in a limited number of vertebrates tissues, at high levels only in fast-contracting muscles and at lower levels in brain and several endocrine tissues Endo et al., (1985) developed a specific RIA to parvalbumin (PV) and detecteed PV in the ovary as well as pituitary, thyroid, adrenal, and testes.
Pohl et al., (1995) described the presence of PV and its transcripts, analyzed by immunohistochemistry and in situ hybridization, respectively, during the postnatal development of the rat ovary. In ovaries 1-16 days old, neither PV mRNA nor PV was observed. By contrast, starting from day 18 postpartum, both PV mRNA and PV were detected in low amounts, simultaneously with the onset of differentiation of secondary intestitial gland cells in the ovarian interfollicular stroma. PV and its transcripts were primarily detected in conspicuous patches of interstitial gland tissue and in the differentiated thecal cells around the large follicles, and PV appeared to be fully expressed 33 days after birth. The parallel time courses of PV mRNA and PV accumulation during developmental differentiation, and the appearance of a steroid-producing cellular phenotype as well as the strict cellular colocalization of these two features, strongly suggest involvement of PV in the steroid metabolism of these cells. Pohl et al., (1995) also showed that suppression of gonadotrophic hormone production by hypophysectomy of adult rats totally suppresses PV production in parallel with the disappearance of the morphological features typical of steroid-producing cells in the remaining interstitial tissue of the ovary.
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