Differential effects of selective beta 1-agonist stimulation on epi- and endocardial XXXX tension in anesthetized @entity235 .

@entity10342 @entity235 @entity26 @entity73180 @entity3044 @entity551 @entity4095 @entity2179
We investigated the effects of selective beta 1 adrenoceptor stimulation on @entity26 tension ( @entity4095 ) in the myocardium of anesthetized @entity235 . A beta 1-selective full agonist, @entity73180 (0.01-0.05 microgram/kg, i.v.), caused positive inotropic and chronotropic effects, and increased left circumflex blood flow, although it did not change arterial blood pressure. These effects were inhibited by @entity2179 (10 micrograms/kg), but not by @entity10342 (30 micrograms/kg). Under control conditions, subepicardial @entity4095 ( @entity4095 epi) and subendocardial @entity4095 (pO2endo) were approximately 33 and 27 mmHg, respectively. @entity73180 (0.05 microgram/kg) decreased pO2epi in all cases, with a mean decrease of 2.6 +/- 0.5 mmHg, and this was significantly inhibited by @entity2179 . @entity73180 caused an increase (7 out of 10 @entity235 ) or a slight decrease (3 out of 10) in the pO2endo; the mean increment was 2.0 +/- 1.3 mmHg (n = 10). @entity3044 (0.01-0.05 microgram/kg, i.v.) exerted positive inotropic and chronotropic effects that were sensitive to @entity2179 , and a @entity551 effect that was sensitive to @entity10342 . @entity3044 caused an increase in blood flow that was sensitive to @entity10342 . @entity3044 (0.05 microgram/kg) decreased pO2epi in all cases, with a mean decrease of 2.7 +/- 0.5 mmHg, which was significantly inhibited by @entity2179 . @entity3044 caused an increase (5 out of 10) or a slight decrease (5 out of 10) in the pO2endo; the mean increment was 1.1 +/- 1.2 mmHg (n = 10).(ABSTRACT TRUNCATED AT 250 WORDS)
