Effects of newly synthesized amino acids containing thiazole residues on electrically evoked smooth muscle contractions.
New amino acids containing thiazole residues have been synthesized and in vitro experiments were performed to study their action on neurotransmission in target tissues with adrenergic and cholinergic neurotransmission. Acetaminothiazoles, structurally related to the novel class, are known to act as H1 agonists, therefore, the effects of the newly synthesized Ala- and Pro-thiazole derivatives on smooth muscle contractile activity were compared to those of histamine (HA). The experiments were carried out on electrically stimulated prostatic part of rat and rabbit vasa deferentia and proximal guinea pig ileum. HA had biphasic effect on electrically evoked neurogenic contractions of guinea pig ileum, Pro(Thz) had a stimulating effect, while Ala(Thz) had no effect. The histamine H1-receptor antagonist diphenhydramine inhibited the Pro(Thz)-induced spontaneous contractile activity in the longitudinal layer of guinea pig ileum. HA had a biphasic effect on electrically induced neurogenic contractions of rat and rabbit vasa deferentia while Pro(Thz) and Ala(Thz) inhibited the ES-contractions. The present results show that the newly synthesized compounds might affect the electrically evoked smooth muscle contractions. Some similarity in the effects of HA and of the new substances was observed.
Stanchev
M
M
Institute of Molecular Biology, Bulgarian Academy of Sciences, Sofia, Bulgaria. mincho@bgcict.acad.bg
Bocheva
A
A
Todorov
S
S
Golovinsky
E
E
D000596:Amino Acids / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D004558:Electric Stimulation; D066298:In Vitro Techniques; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D051379:Mice; D015394:Molecular Structure; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects* / Q000502:physiology; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar; D013055:Spectrophotometry, Infrared; D013844:Thiazoles / Q000032:analysis*
D000596:Amino Acids; D013844:Thiazoles