خيارات البحث
النتائج 111 - 120 من 271
Effects of substance P on nicotine-induced intracellular Ca2+ dynamics in bovine adrenal chromaffin cells
1999
Suzuki, S. (Hokkaido Univ., Sapporo (Japan)) | Habara, Y. | Kanno, T.
Substance P (SP) is colocalized with ACh in splanchnic nerves that innervate into adrenal medulla and the peptide has been shown to inhibit nicotinic agonists-induced catecholamine secretion. To elucidate the effects of SP on cytosolic Ca(2+) dynamics, the present study was conducted using fura-2-loaded isolated bovine adrenal chromaffin cells. Stimulation of the cells with nicotine (10-100mu-M) produced a rapid rise of cytosolic Ca(2+) concentration ([Ca(2+)]i), the peak level of which increased in a dose-dependent manner, followed by a gradual decay. In the presence of 10mu-M SP, the dose-response relationship of the peak levels shifted downward. Quantitative analyses implied that SP inhibits the nicotine-induced Ca(2+) influx in a noncompetitive manner. Nicotinic acetylcholine receptor is composed of two major functional domains: an agonist-binding site and an ionophore or channel domain. Agonist binding activates ionophore / channel domain and causes mainly Na(+) influx. This Na(+) influx depolarizes the cell and activates voltage-dependent Ca(2+) channels. Based on this fact, the present results indicate that SP dose not block nicotine binding sites but interferes with other sites of nicotinic receptor / channel molecule, most probably a channel domain. It was suggested that SP colocalized with ACh in splanchnic nerves functions as a physiological modulator of catecholamine secretion by non-competitively suppressing ACh-induced cytosolic Ca(2+) dynamics in bovine a
اظهر المزيد [+] اقل [-]Haemoproteus Columbae in domestic pigeons in Sebele, Gaborone, Botswana
1999
Mushi, E.Z. (Botswana College of Agriculture, Gaborone (Botswana). Animal Science and Production) | Binta, M.G. | Chabo, R.G. | Mathaio, M. | Ndebele, R.T.
The epidemiology of rabies in Zimbabwe. 1. Rabies in dogs (Canis familiaris)
1999
Bingham, J. | Foggin, C.M. (Central Veterinary Laboratory, Harare (Zimbabwe)) | Wandeler, A.I. | Hill, F.W.G.
Parasites of domestic and wild animals in South Africa. XXXVI. Arthropod parasites of yellow mongooses, Cynictis penicillata (G. Cuvier, 1829)
1999
Horak, I.G. | Chaparro, F. (Pretoria Univ., Onderstepoort (South Africa). Dept. of Veterinary Tropical Diseases) | Beaucournu, J.-C. | Louw, J.P.
The use of chicken IgY in a double antibody sandwich ELISA for detecting African horsesickness virus
1999
Du Plessis, D.H. | Van Wyngaardt, W. | Romito, M. (Agricultural Research Council, Onderstepoort (South Africa). Onderstepoort Veterinary Inst.) | Du Plessis, M. | Maree, S.
Effect of an aqueous extract of Azadirachta indica on the immune response in mice
1999
Njiro, S.M. (Nairobi Univ. (Kenya). Dept. of Veterinary Pathology and Microbiology) | Kofi-Tsekpo, M.W.
Gastro-intestinal parasites of cattle in the communal grazing system of Botshabelo in the Free State [South Africa]
1999
Dreyer, K. | Fourie, L.J. | Kok, D.J. (Orange Free State Univ., Bloemfontein (South Africa). Dept. of Zoology and Entomology)
Ecological studies of helminth parasites of the largemouth bass, Micropterus salmoides, from Lake Naivasha and the Oloidien bay, Kenya
1999
Aloo, P.A. (Aquatic Research Centre, Nairobi (Kenya))
Assessment of cattle owners' perceptions and expectations, and identification of constraints on production in a peri-urban, resource-poor environment
1999
Dreyer, K. | Fourie, L.J. | Kok, D.J. (Orange Free State Univ., Bloemfontein (South Africa). Dept. of Zoology and Entomology)
The parasitological and serological prevalence of tsetse-transmitted bovine trypanosomosis in the Eastern Caprivi (Caprivi District, Namibia)
1999
Van den Bossche, P. | Mudenge, D. (Regional Tsetse and Trypanosomosis Control Programme, Harare (Zimbabwe)) | Mubanga, J. | Norval, A.
