Cardiovascular Dynamics in Swimming Adult Sockeye Salmon

1967 ◽  
Vol 24 (8) ◽  
pp. 1775-1790 ◽  
Author(s):  
L. S. Smith ◽  
J. R. Brett ◽  
J. C. Davis

Dorsal aortic blood pressure, heart rate, and oral water pressure were recorded in adult sockeye salmon (Oncorhynchus nerka) while they were resting in darkened aquaria or swimming in an illuminated tunnel-respirometer. Pressures were recorded on an oscillograph attached to pressure transducers connected with cannulae in the dorsal aorta and oral cavity. The velocity of the water in the swimming chamber was increased in stepwise fashion every 30 min until the fish stopped swimming and were swept against an electrified grid. At the cessation of swimming, which was considered as the onset of fatigue, water velocity was decreased to a minimum which permitted the fish to rest and dorsal aortic blood pressure, heart rate, and oral water pressure were recorded for about 1 hr as they returned toward resting levels. Resting values were 44/38 mm Hg (systolic/diastolic) and 49 heartbeats/min. At maximal swimming speed dorsal aortic blood pressure was 55/49 mm Hg and heart rate was 83 beats/min. No abrupt changes in cardiovascular function occurred at the onset of fatigue.A number of morphological (length and weights of the body and ventricle) and cardiovascular (pressures, rates) variables were measured in six adult sockeye salmon. A significant correlation was found between hematocrit, ventricle weight, and heart rate; a change in one apparently caused adjustments in the other two in order to maintain a constant supply of oxygen to the tissues during subfatigue levels of activity.The effects of removal and replacement of blood or isotanic saline in the dorsal aorta were observed in three adult sockeye salmon. Removal of blood produced a proportionate decrease in blood pressure and an increase in heart rate. Neither dilution of the blood by replacement with saline nor increase in blood volume from addition of saline had any significant effect on heart rate and blood pressure.

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Bernard I. Levy ◽  
Jean-Guillaume Dillinger ◽  
Patrick Henry ◽  
Damien Logeart ◽  
Stephane Manzo Silberman ◽  
...  

Background: Treatment of hypertensive patients with beta-blockers reduces heart rate (HR) and increases central blood pressure, implying that the decrease in HR could explain reported increases in cardiovascular risk with beta-blocker. This analysis from a randomized, double-blind study explores whether HR reduction with the I f inhibitor ivabradine had an impact on central blood pressure and coronary perfusion. Methods and results: We included 12 normotensive patients with stable CAD, HR ≥70 bpm (sinus rhythm), and stable background beta-blocker therapy. Patients received ivabradine 7.5 mg bid or matched placebo for two 3-week periods with a crossover design and evaluation by aplanation tonometry. Treatment with ivabradine was associated with a significant reduction in resting HR after 3 weeks versus no change with placebo (-15.8±7.7 versus +0.3±5.8 bpm, p=0.0010). There was no relevant between-group difference in change in central aortic SBP (-4.0±9.6 versus +2.4±12.0 mm Hg, p=0.13) or augmentation index (-0.8±10.0% versus +0.3±7.6%, p=0.87). Treatment with ivabradine was associated with prolongation of diastolic perfusion time by 41% from baseline to 3 weeks (+215.6±105.3 versus -3.0±55.8 ms with placebo, p=0.0005) (Figure) and with a pronounced increase in an index of myocardial viability (Buckberg index, +39.3±27.6% versus -2.5±13.5% with placebo, p=0.0015). There were no safety issues during the study. Conclusion: Heart rate reduction with ivabradine does not modify central aortic blood pressure and is associated with a marked prolongation of diastolic perfusion time and an improvement in myocardial perfusion.


1997 ◽  
Vol 272 (2) ◽  
pp. R607-R614 ◽  
Author(s):  
E. C. Bowman ◽  
G. P. Roderick ◽  
S. R. Bloom ◽  
A. V. Edwards

Ingestion of milk during suckling causes hypertension and tachycardia in young, unweaned animals of many species, but these responses are most pronounced in the calf. The present study was undertaken to assess the extent to which this phenomenon depends on activation of adrenoceptors in these animals. Mean basal heart rate was 100 +/- 8 beats/min and mean basal aortic blood pressure was 92 +/- 5 mmHg. The rise in heart rate during feeding was almost completely suppressed after propranolol (2-4 mg/kg iv), which also significantly reduced the rise in blood pressure from 67 +/- 4 to 44 +/- 3 mmHg (P < 0.005). Additional pretreatment with phentolamine (1.0 mg/kg and < or =0.1 mg x min(-1) x kg(-1) iv) virtually eliminated the rise in blood pressure during feeding; it rose by only 8 +/- 4 mmHg (P < 0.001). Section of both splanchnic nerves also significantly reduced the rise in blood pressure during feeding, especially after pretreatment with propranolol. Neither section of the splanchnic nerves nor the administration of the blocking agents significantly affected the rises in plasma insulin and pancreatic polypeptide that occurred after feeding. There was no detectable rise in plasma neuropeptide Y concentration in response to feeding. The hypertensive response to direct electrical stimulation of the peripheral end of a splanchnic nerve and to intra-arterial injections of norepinephrine were completely abolished after combined pretreatment with atropine, propranolol, and phentolamine after the ipsilateral adrenal vein had been tied off. It is concluded that the cardiovascular changes that occur during feeding in these animals are attributable very largely, if not entirely, to activation of adrenoceptors.


2003 ◽  
Vol 95 (2) ◽  
pp. 751-757 ◽  
Author(s):  
A. S. Thakor ◽  
C. N. Brown ◽  
A. V. Edwards

Submandibular vascular and secretory responses to parasympathetic chorda-lingual (C-L) stimulation were investigated in anesthetized sheep before, during, and after an intracarotid (ic) infusion of endothelin-1 (ET-1). Stimulation of the peripheral end of the C-L nerve at 4 and 8 Hz produced a frequency-dependent reduction in submandibular vascular resistance (SVR) associated with a frequency-dependent increase in submandibular blood flow, salivary flow, and Na+, K+, and protein output from the gland. During stimulation at 4 Hz, ic ET-1 significantly increased SVR ( P < 0.01), without significantly affecting either the aortic blood pressure or heart rate. Submandibular blood flow (SBF) was reduced by 48 ± 4% and the flow of saliva by 50 ± 1%. The effect on blood and salivary flow persisted for at least 30 min after the infusion of ET-1. The reduction in SBF was associated with a diminution in the output of Na+,K+, and protein in the saliva ( P < 0.01). These effects persisted for 30 min after the infusion of ET-1 had been discontinued and were linearly related to the flow of plasma throughout.


1985 ◽  
Vol 117 (1) ◽  
pp. 335-347 ◽  
Author(s):  
D. G. Smith ◽  
S. Nilsson ◽  
I. Wahlqvist ◽  
B. M. Eriksson

Dorsal (PDA) and ventral aortic blood pressure (PVA) and heart rate (HR) were measured in conscious resting cod, Gadus morhua L., which has been allowed 24 h recovery from surgery. Plasma adrenalin and nonadrenalin concentrations in these fish were 3.4 and 2.2 nmoll-1 respectively, and thus lower than previously reported values from partially recovered cod. Twenty-four hours after treatment with the adrenergic neurone blocking agent bretylium, PDA was significantly reduced by 17% compared to sham-injected controls, although PVA and heart rate were unaltered. Subsequent alpha-adrenoceptor blockade by phentolamine produced no further fall in PDA and no changes in PVA or HR, provided a 5-h period was allowed to overcome the acute toxic side effects of phentolamine. The effectiveness of the bretylium or phentolamine blockade was confirmed by noting the absence of any vasoconstrictor response during sympathetic nerve stimulation in perfused tails from fish used in the in vivo experiments. Bretylium had no significant effect on the sensitivity of the isolated coeliac artery to adrenalin, but effectively blocked the adrenergic innervation of this artery or the vasculature of the tail. Evidence for a non-selective blockade of non-adrenergic nerves to the heart was also obtained. It is concluded that the adrenergic tonus affecting the dorsal aortic blood pressure in resting cod that have recovered for 24 h following surgery is due solely to an adrenergic nervous tone.


2021 ◽  
Vol 20 ◽  
pp. 153473542199523
Author(s):  
Anna Hohneck ◽  
Christina Reyser ◽  
Kirsten Merx ◽  
Simone Weingärtner ◽  
Athanasios Mavratzas ◽  
...  

Background: Music therapy or sound interventions were shown to confer beneficial effects in patients with cancer for instance in terms of pain or fear relief and improvement of other patient reported outcomes. Cardiovascular parameters, especially heart rate variability (HRV) were found to have prognostic implications in cancer patients. In this trial we aimed to investigate the effects of a sound intervention on cardiovascular parameters compared to rest in patients with cancer. Methods and results: Using a randomized cross-over design, 52 patients (male 13, female 39) with cancer were recruited to receive both a 15-minute sound intervention and a 15-minute rest intervention within 4 weeks with at least a one-week blanking period. Cardiovascular parameters (among others HRV, aortic pulse wave velocity [PWV], augmentation index [Aix], aortic blood pressure [BP], heart rate [HR]) were assessed immediately before (pre) and after (post) the intervention had taken place. HRV (Root mean square of successive RR interval differences [RMSSD, ms]) significantly increased, during sound intervention (median RMSSD pre 24 [range 5-112] vs post 22 [range 9-141], P = .03). Likewise, median PWV, as a direct marker of arterial stiffness, was significantly reduced by sound intervention ([m/s] pre 8.5 [range 5.6-19.6] vs post 8.3 [range 5.6-15.6], P = .04). For both parameters no statistically significant change during rest was observed. HR was lowered by both, rest ( P < .0001) and sound intervention ( P = .02), with a more pronounced effect by rest. A significant increase in systolic aortic blood pressure was shown by rest ([mmHg] median 101 [range 78-150] vs post median 103 [range 71-152], P = .04) but not during sound intervention ( P = .59), while rest intervention led to a decrease in resistance index (pre median 33 [range 13-92] vs post median 32 [11-84], P = .02). Conclusion: In comparison with rest, a single sound intervention in patients with cancer improved cardiovascular parameters commonly associated with increased stress levels. Studies with longer follow-up and multiple interventions are warranted. Trial Registration: ISRCTN registry 70947363.


1964 ◽  
Vol 207 (6) ◽  
pp. 1325-1329 ◽  
Author(s):  
David E. Donald ◽  
John T. Shepherd

In three normal dogs and in six dogs with cardiac denervation, there was a rapid increase in cardiac output (electromagnetic flowmeter) from the start of exercise. The denervated group showed an average delay of 25 sec in reaching plateau values of cardiac output and a deficit of 18% in the accumulated flow over the first minute of running; augmentation of output was due principally to a rapid increase in stroke volume since acceleration of heart rate was slow. In normal dogs, the augmentation of output came from a rapid increase in heart rate. The steady-state values for cardiac output and oxygen consumption were similar in the two groups as was the pattern of oxygen consumption in the first minutes of exercise and the manner in which the oxygen debt was repaid. This suggested that the denervated dogs extracted more oxygen from the circulating blood in the first moments of running. The changes with exercise in aortic blood pressure were similar in the two groups.


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