| RESEARCH PAPER
|Year : 1989 | Volume
| Issue : 3 | Page : 81-89
Differential effects of calcium and sodium on the mechanical responses to various agonists in rat vas-deferens and anococcygeus muscle
RH Razdan, AA Mehta, RK Goyal
1. Noradrenaline (NA), 5-hydroxytryptamine (5-HT) phenylephrine (PHE), methoxamine (ME), dopamine (DA) and carbachol produced dose dependent contraction of rat vas-deferens and rat anococcygeus muscle.
2. In presence of D-600 (41 uM) or in calcium free PSS, the responses to NA, 5-HT and carbachol were not affected significantly, whereas the responses to PHE, ME and DA were significantly decreased as compared to the control in rat anococcygeus muscle.
3. However, in rat vas-deferens, all these agonists failed to produce any response in the preparation bathed in Ca++ free PSS or PSS containing D-600.
4. Indanidine (Sgd 101/75) produced dose dependent contraction of rat anococcygeus and rat vasdeferens. The contractile responses to indanidine in rat anococcygeus muscle were comparable to that of NA (about 75%), however, in rat vas-deferens it was of smaller magnitude (17% of NA max).
5. In rat anococcygeus and in rat vas-deferens the responses to indanidine were abolished in the presence of D-600 or Ca++ free PSS.
6. In zero sodium the responses to NA, PHE, 5-HT, DA, ME and carbachol were not affected significantly in either rat anococcygeus or vas-deferens. However the responses to indanidine were significantly inhibited in rat anococcygeus. While in rat vas-deferens, indanidine failed to produce any contraction in zero sodium.
7. It is concluded that there may be different post receptor regulatory mechanisms controlling calcium movements responsible for the contraction of rat anococcygeus and rat vas-deferens.
R H Razdan
Source of Support: None, Conflict of Interest: None