Open AccessDevelopmental changes in .ALPHA.-adrenergic and muscarinic receptor-mediated contractions of rat vas deferens.
Author(s) -
Hiroshi Handa,
Kunio Takeyasu,
Yasuhiro Watanabe,
Shuji Uchida,
Hiroshi Yoshida
Publication year - 1982
Publication title -
japanese journal of pharmacology/japanese journal of pharmacology
Language(s) - English
Resource type - Journals
eISSN - 1347-3506
pISSN - 0021-5198
DOI - 10.1254/jjp.32.671
Subject(s) - vas deferens , muscarinic acetylcholine receptor , endocrinology , medicine , adrenergic receptor , acetylcholine , atropine , ed50 , receptor , norepinephrine , chemistry , adrenergic , acetylcholine receptor , alpha (finance) , cholinergic , biology , dopamine , construct validity , nursing , patient satisfaction
Studies were made on developmental changes in phasic contractions of isolated rat vas deferens in response to norepinephrine (NE) and acetylcholine (ACh), which are mediated by alpha-adrenergic and muscarinic cholinergic receptors (alpha-R and m-R). The ED50 values of both contractions were almost constant during development, but the maximum responses to NE and ACh per wet weight and the relative contractions by NE and ACh to that by 100 mM K+ decreased greatly between 3 and 8 weeks after birth. However, the alpha- and m-receptors, assayed by measuring binding of [3H]-WB4101 and [3H]-quinuclidinyl benzylate (QNB), increased quantitatively per g wet weight and per mg protein between 2 and 8 weeks after birth, but did not change qualitatively. Thus, a discrepancy between the increases of alpha- and m-receptors and decreases of the maximum responses to NE and ACh was found, and possible mechanisms for this are discussed.