Alpha-adrenergic pathways in the lateral hypothalamus are important for the dipsogenic effect of carbachol injected into the medial septal area.
Braz J Med Biol Res
; 28(2): 240-5, 1995 Feb.
Article
em En
| MEDLINE
| ID: mdl-7581048
We studied the effect of the alpha 1- and alpha 2-adrenergic receptors of the lateral hypothalamus (LH) on the control of water intake induced by injection of carbachol into the medial septal area (MSA) of adult male Holtzman rats (250-300 g) implanted with chronic stainless steel cannulae into the LH and MSA. The volume of injection was always 1 microliter and was injected over a period of 30-60 s. For control, 0.15 M NaCl was used. Clonidine (20 nmol) but not phenylephrine (160 nmol) injected into the LH inhibited water intake induced by injection of carbachol (2 nmol) into the MSA, from 5.4 +/- 1.2 ml/h to 0.3 +/- 0.1 and 3.0 +/- 0.9 ml/h, respectively (N = 26). When we injected yohimbine (80 nmol) + clonidine (20 nmol) and prazosin (40 nmol) + clonidine (20 nmol) into the LH, water intake induced by injection of carbachol into the MSA was inhibited from 5.4 +/- 1.2 ml/h to 0.8 +/- 0.5 and 0.3 +/- 0.2 ml/h, respectively (N = 19). Water intake induced by carbachol (2 nmol) injected into the MSA was decreased by previous injection of yohimbine (80 nmol) + phenylephrine (160 nmol) and prazosin (40 nmol) + phenylephrine (160 nmol) from 5.4 +/- 1.2 ml/h to 1.0 +/- 0.7 and 1.8 +/- 0.8 ml/h, respectively (N = 16). The cannula reached both the medial septal area in its medial portion and the lateral hypothalamus. It has been suggested that the different pathways for induction of drinking converge on a final common pathway.(ABSTRACT TRUNCATED AT 250 WORDS)
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Carbacol
/
Receptores Colinérgicos
/
Receptores Adrenérgicos alfa
/
Ingestão de Líquidos
/
Região Hipotalâmica Lateral
Limite:
Animals
Idioma:
En
Revista:
Braz J Med Biol Res
Ano de publicação:
1995
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Brasil