Tulsi Prajna 1994 10

SR No.: 524581
Original Sutra Author: N/A
Author: Parmeshwar Solanki
Publisher: Jain Vishva Bharati
Publication Year: 1994
Total Pages: 152
Language: Hindi
Classification: Magazine, India_Tulsi Prajna, & India
File Size: 7 MB

Page 129

18
TULSI-PRAJNA
produce vasoconstriction. These alpha receptors are probably closer to the lumen than those that respond to norepinephrine released from sympathetic nerve endings Alpha and beta receptors have been divided into two subtypes based on their relative sensitivities to different agonists. A beta-adrenergic vasodilating mechanism has recently been discovered in the finger by injecting isoproterenol, a synthetic beta-adrenergic agonist, into the brachial artery and then blocking this effect with propanolol, a beta-adrenergic antagonists (Cohen & Coffmann, 1981). However an endogenous ligand that acts of these beta receptors has not yet been found.
The sensitivities of vascular adrenergic receptars change according to temperature and represept one means of local control of blood flow. Other local influences include changes in blood gases and metabolism, myogenic tone, and the axon reflex (Vanhoutte, 1980).
Self-Control of Finger Blood Flow-Studies in Normal Subjects
Early investigations of self-induced vasodilation combined the effects of procedures such as finger temperature biofeedback, monetary rewards, and suggestions of thermal imagery. For example, Taub and Emurian (1976) reported an uncontrolled study in which 9 subjects were trained to increase and 12 subjects were trained to decrease hand temperature using feedback. Subjects were also encouraged to use tbermal imagery and nine subjects received monetary rewards for changes in temperature. The authors stated that clear evidence of learning usually occurred within four sessions and that the average temperature change per session was approximately 1.20° C. Two subjects, selected on the basis of superior performance, were given additional training to increase and decrease temperature and showed changes of 5°C to 7.70 C.
The controlled studies, subsequently performed by Surwit et al, (1976), failed to demonstrate significant elevations in finger temperature using biofeedback and monetary rewards. In the first study, two groups of 8 subjects each received training to either increase or decrease finger temperature. Half the subjects in each group received 7 training sessions and half received 11 sessions. Although the decrease group produced significant temperature declines (-2.0° C), the elevations shown by the increase group (0.250 C) were nonsigni. ficant. Varying the number of training sessions had no effect. The authors hypothesized that the poor performance of the increase subjects might have been due to their approaching maximal finger temperature levels. They therefore trained 8 additional subjects in a