title: Extra and intracellular calcium signaling pathway(s) differentially regulate histamine-induced myometrial contractions during early and mid-pregnancy stages in buffaloes (Bubalus bubalis).
abstract: This study examines the differential role of calcium signaling pathway(s) in histamine-induced uterotonic action during early and mid-pregnancy stages in buffaloes. Compared to mid pregnancy, tonic contraction, amplitude and mean-integral tension were significantly increased by histamine to produce myometrial contraction during early pregnancy with small effects on phasic contraction and frequency. Although uterotonic action of histamine during both stages of pregnancy is sensitive to nifedipine (a L-type Ca2+channels blocker) and NNC55-0396 (T-type Ca2+channels blocker), the role of extracellular calcium seems to be more significant during mid-pregnancy as in this stage histamine produced only 9.38±0.96% contraction in Ca2+free-RLS compared to 21.60±1.45% in uteri of early pregnancy stage. Intracellular calcium plays major role in histamine-induced myometrial contraction during early pregnancy as compared to mid pregnancy, as in the presence of cyclopiazonic acid (CPA) Ca2+-free RLS, histamine produced significantly higher contraction in myometrial strips of early-pregancy in comparison to mid-pregnancy (10.59±1.58% and 3.13±0.46%, respectively). In the presence of U-73122, the DRC of histamine was significantly shifted towards right with decrease in maximal effect (Emax) only in early pregnancy suggesting the predominant role of phospholipase-C (PL-C) in this stage of pregnancy.
authors.affiliation: Experimental Pharmacology Laboratory, Department of Pharmacology and Toxicology, College of Veterinary Science and Animal Husbandry, UP Pandit Deen Dayal Upadhyaya Pashu Chikitsa Vigyan Vishwavidyalaya Evam Go-Anusandhan Sansthan, Mathura, U.P., 281 001, India.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Sharma
authors.affiliation: Experimental Pharmacology Laboratory, Department of Pharmacology and Toxicology, College of Veterinary Science and Animal Husbandry, UP Pandit Deen Dayal Upadhyaya Pashu Chikitsa Vigyan Vishwavidyalaya Evam Go-Anusandhan Sansthan, Mathura, U.P., 281 001, India.
authors.forename: Udayraj P
authors.initials: UP
authors.lastname: Nakade
authors.affiliation: Experimental Pharmacology Laboratory, Department of Pharmacology and Toxicology, College of Veterinary Science and Animal Husbandry, UP Pandit Deen Dayal Upadhyaya Pashu Chikitsa Vigyan Vishwavidyalaya Evam Go-Anusandhan Sansthan, Mathura, U.P., 281 001, India.
authors.forename: Soumen
authors.initials: S
authors.lastname: Choudhury
authors.affiliation: Experimental Pharmacology Laboratory, Department of Pharmacology and Toxicology, College of Veterinary Science and Animal Husbandry, UP Pandit Deen Dayal Upadhyaya Pashu Chikitsa Vigyan Vishwavidyalaya Evam Go-Anusandhan Sansthan, Mathura, U.P., 281 001, India.
authors.forename: Rajkumar Singh
authors.initials: RS
authors.lastname: Yadav
authors.affiliation: Experimental Pharmacology Laboratory, Department of Pharmacology and Toxicology, College of Veterinary Science and Animal Husbandry, UP Pandit Deen Dayal Upadhyaya Pashu Chikitsa Vigyan Vishwavidyalaya Evam Go-Anusandhan Sansthan, Mathura, U.P., 281 001, India. Electronic address: profsatish@gmail.com.
authors.forename: Satish Kumar
authors.initials: SK
authors.lastname: Garg
mesh_terms: D000818:Animals; D002020:Buffaloes / Q000502:physiology*; D002118:Calcium / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology; D020013:Calcium Signaling / Q000502:physiology*; D005260:Female; D006632:Histamine / Q000494:pharmacology*; D009215:Myometrium / Q000187:drug effects*; D009543:Nifedipine / Q000494:pharmacology; D011247:Pregnancy; D046509:Tissue Culture Techniques / Q000662:veterinary; D014590:Uterine Contraction / Q000187:drug effects*
chemical_list: D002121:Calcium Channel Blockers; D006632:Histamine; D009543:Nifedipine; D002118:Calcium
keywords: Buffalo myometrium; Calcium; Histamine; PL-C; SERCA; Stages of pregnancy