The Significance of the Effects of Catha edulis Forsk on Electrical Activities of the Heart and some Lung Function Indices

Sewiye, Yohannes Mengiste (2004) The Significance of the Effects of Catha edulis Forsk on Electrical Activities of the Heart and some Lung Function Indices. Masters thesis, Addis Ababa University.

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Abstract

The chewing and ingestion of fresh and young leaves of khat produces observable alterations in the physical, physiological and psychological wellbeing of man. The aim of this study was to assess the effects of Khat on vital signs, lung function indices and electrocardiographic profile of the casual user. Sixty healthy adult men who were casually chewing Khat leaves were randomly selected from 10 localities in Addis Ababa using inclusion and exclusion criteria. The mean age (±SD) was 31±2 years; their mean body weight was 70.8±3.8 kgs, their BMI was 22.3±0.6 kg/m2 Each of the subjects was given 200 gm of fresh Beleche leaves to chew for a period of two hours. All vital signs including arterial blood pressure, heart rate, and respiratory rate increased significantly (P<0.001). Measurements of VCIn, FVC, FEV1, FEF and PEFR showed statistically significant differences between pre-test and post-test values (P<0.001). The mean value of the post-test FEV1% showed significant increment in only about 70% of the study subjects. The changes in VCIN, FVC, FEV1 and PEFR appeared to be relatively more consistent and significant (P<0.001). Khat alkaloids apparently activate β-adrenergic receptors in the respiratory system and bring about the overall changes seen on lung volume and capacities, which reflect bronchial dilation. Other important changes observed in this study were ECG changes. Following chewing and ingestion of khat the overall ventricular depolarization and conduction velocity (QRS) increased by 11%; the cardiac cycle length (R-R interval) was shortened by 9% and this hastened the ventricular depolarization and repolarization time (QT interval) by4.5%. The effects observed on the cardiovascular variables possibly are mediated through activation of ∝- and β-adrenelgic receptors localized in the atria and ventricles, respectively. The active ingredients of Khat have sympathetic- like effects on conductivity, rhythmicity and excitability of the heart. . None were smokers and their frequency of chewing and ingestion of khat leaves was on the average 1.7 times per week. All study subjects had a normal P/E and history and normal V/S, LFI and ECG prior to the khat session. Other observations in this study were increased energy level and alertness in almost all study subjects following khat ingestion for two hours. These could be parts of the central actions of cathinone, a lipophilic ingredient of khat that can easily traverse the Blood-Brain-Barrier. The cardiopulmonary responses to khat use and the objectively observable behavioral (central) effects are significantly marked in the present investigation but further studies must be conducted to get an insight into: a) The effects of long-term and chronic use of khat on cardiopulmonary functions, b) The peripheral and central effects of quick ingestion of khat juice.

Item Type: Thesis (Masters)
Subjects: Q Science > QP Physiology
R Medicine > R Medicine (General)
Divisions: Africana
Depositing User: Vincent Mpoza
Date Deposited: 21 Jun 2018 06:19
Last Modified: 21 Jun 2018 06:19
URI: http://thesisbank.jhia.ac.ke/id/eprint/5228

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