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Biomedical subjects

A Gulati

Publications and source records attributed to A Gulati.

At least 19 recordsLinked to original sources

Evidence for antagonistic activity of endothelin for clonidine induced hypotension and bradycardia.

Effect of endothelin (ET) on clonidine induced cardiovascular effects was studied in male Sprague-Dawley rats. Clonidine (75 micrograms/kg, iv) produced significant decrease in blood pressure and heart rate. ET-1 (50 ng/kg, iv) pretreatment completely antagonized the hypotension and bradycardia induced by clonidine. ET-2 (50 ng/kg, iv) and ET-3 (50 ng/kg, iv) had similar antagonistic effect on clonidine induced hypotension and bradycardia. The antagonistic effect of ET lasted for several hours, however, 4 hours after ET pretreatment only partial blockade of clonidine induced hypotension and bradycardia was observed. This indicated that the antagonistic effect of ET was reversible. Initial hypertensive response induced by high dose of clonidine (750 micrograms/kg, iv) could not be antagonized by ET-1, ET-2 or ET-3, while phenoxybenzamine, an alpha adrenoceptor antagonist, blocked the hypertensive response of clonidine. Thus, ET has no antagonistic effect on the initial hypertensive response but antagonizes the hypotensive and bradycardic effect induced by clonidine. Clonidine induced hypotension and bradycardia are mediated through central alpha 2 adrenoceptors while hypertension is mediated through peripheral alpha 2 adrenoceptors. It is concluded that central alpha 2 adrenoceptors are different from peripheral alpha 2 adrenoceptors and ET antagonizes the effect of clonidine only on central alpha 2 adrenoceptors but has no antagonistic activity on peripheral alpha 2 adrenoceptors.

Animals

Ontogeny of endothelin and its receptors in rat brain.

The ontogeny of endothelin (ET) system in rats was studied in preterm (18 days of gestation), term (21 days of gestation) and 1 week post term rats. Brains were dissected out and (1) processed for the estimation of endogenous ET-1 by RIA and (2) membranes were prepared for radioreceptor binding. Receptor characteristics, affinity (Kd) and density (Bmax) were determined using [125I] ET-1 and [125I] SRT 6b (which is structurally similar to ET) and cold ET-1 or SRT 6b as displacer. ET levels were found to be 25.66 +/- 3.18 pg/g protein in preterm, 47.37 +/- 5.31 pg/g protein in term and 48.30 +/- 1.90 pg/g protein in post term rats. ET levels were significantly lower in preterm as compared to term and post term rats. Preterm, term and post term rats showed single high affinity binding site for both [125I] ET-1 and [125I] SRT 6b. The Kd values for [125I] ET-1 and [125I] SRT 6b binding were similar in preterm, term and post term rats. The Bmax values of both [125I] ET-1 and [125I] SRT 6b binding were found to be similar in preterm and term rats while they were significantly higher in post term rats. In adult (4 month old) rats the Kd values were similar to neonatal rats while the Bmax values were significantly lower than the post term neonatal rats. It is concluded that ET and its receptors are developmentally regulated and there is a possibility that endogenous ET is involved in the regulation of ET receptor density.

Animals

Down-regulation of central receptors for thyrotropin-releasing hormone in kappa opiate agonist-induced abstinence in the rat.

The effect of U-50,488H, a selective kappa opiate agonist, on tolerance-dependence and abstinence on the TRH receptors of the spinal cord and discrete regions of the brain of male Sprague-Dawley rats was determined. Rats were injected intraperitoneally twice daily with 25 mg/kg of U-50,488H for 4 days. Rats serving as controls were injected with the vehicle. On day 5, rats which were labeled as tolerant to U-50,488H were injected with U-50,488H (25 mg/kg) and sacrificed 1 hr later, whereas those labeled as abstinent were sacrificed without any injection. The above procedure has been previously shown to produce a high degree of tolerance to the analgesic and hypothermic effects of U-50,488H. The spinal cord and regions of the brain (hippocampus, cortex, midbrain, hypothalamus, corpus striatum, pons and medulla, and amygdala) were isolated for binding studies. The ligand [3H]MeTRH was used for TRH receptors. The binding constants, Bmax and Kd values, of [3H]MeTRH to bind to membranes prepared from various regions of the brain and spinal cord of rats tolerant-dependent on U-50,488H were unaffected. However, in rats abstinent to U-50,488H, the binding of [3H]MeTRH to membranes of the hypothalamus, and pons and medulla, was decreased. The decreased binding of [3H]MeTRH to hypothalamic membranes was due to changes in Bmax value, while in pons and medulla it was due to an increase in the Kd value.(ABSTRACT TRUNCATED AT 250 WORDS)

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh

Characteristics of endothelin receptors in the central nervous system of spontaneously hypertensive rats.

The binding of [125I]sarafotoxin 6b (SRT 6b) and [125I]endothelin-1 (ET-1) to endothelin (ET) receptors of neuronal membranes prepared, from regions of the brain and spinal cord of 8 week-old, spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats was determined. Spontaneously hypertensive rats had significantly higher blood pressure as compared to WKY rats. Heart rate was similar in SHR and WKY rats. [125I]SRT 6b and [125I]ET-1 bound to the membranes of the cerebral cortex, hypothalamus, ventrolateral medulla, dorsomedial medulla and spinal cord at a single, high affinity site. The Kd and Bmax values of the binding of [125I]SRT 6b were found to be similar to binding of [125I]ET-1 in all the regions. The concentration-dependent inhibition of binding of [125I]ET-1 by unlabeled ET-1, in spinal cord membranes showed an IC50 value of 2.66 +/- 0.59 nM and a Ki value of 2.35 +/- 0.52 nM in WKY rats and an IC50 value of 2.82 +/- 0.76 nM and a Ki value of 2.43 +/- 0.70 nM in SHR rats. On the other hand, the concentration-dependent inhibition of the binding of [125I]SRT 6b by unlabeled ET-1, in spinal cord membranes showed an IC50 value of 10.31 +/- 1.82 pM and a Ki value of 8.44 +/- 1.41 pM in WKY rats, while SHR rats showed an IC50 value of 10.28 +/- 1.94 pM and a Ki value of 8.89 +/- 2.00 pM. The binding of [125I]SRT 6b and [125I]ET-1 in the cerebral cortex, dorsomedial medulla and spinal cord membranes was found to be similar in SHR and WKY rats.(ABSTRACT TRUNCATED AT 250 WORDS) [corrected]

Animals

Morphine metabolism in acutely ill preterm newborn infants.

To examine the manner in which morphine is metabolized in acutely ill premature infants, we measured the levels of morphine, morphine-3- and -6-glucuronides, and codeine in timed urine specimens and paired plasma specimens at 4 hours and 24 hours after a single dose of morphine in 16 preterm infants (less than 32 weeks of gestational age). A large amount of unmetabolized morphine was found in the urine in 13 (81.2%) of the 16 infants at 4 hours; in 12 of them, morphine was excreted even at 24 hours. Urinary morphine levels varied greatly; the coefficient of variation was 130% at 4 hours and 118% at 24 hours. Codeine was not found in any of the infants. In 10 (62.5%) of the 16 infants, at least one metabolite was found in either plasma or urine. Plasma and urinary levels of morphine conjugates also varied greatly among these 10 infants (coefficient of variation: 109% to 317%). All six infants (37.5%) who had no metabolites excreted large amounts of unmetabolized morphine in the urine for up to 24 hours. Birth weight, gestational age, postnatal age, systemic blood pressure, and other clinical or physiologic variables did not differ significantly between the 10 infants who had morphine conjugates and the six who did not. We conclude that (1) nearly two thirds of acutely ill preterm infants born at less than 32 weeks of gestational age conjugate morphine; (2) irrespective of their ability to produce morphine conjugates, preterm infants excrete large amounts of morphine unmetabolized, as late as 24 hours after a single dose; (3) morphine handling patterns are highly variable among premature infants, and no obvious factors account for the variability; and (4) such variability in morphine handling in general, and the production of the highly potent morphine-6-glucuronide in particular, could explain the variance in morphine pharmacokinetic measures and in the clinical responses to morphine during the newborn period.

Chromatography, High Pressure Liquid

High-performance liquid chromatographic determination of morphine, morphine-3-glucuronide, morphine-6-glucuronide and codeine in biological samples using multi-wavelength forward optical detection.

An isocratic high-performance liquid chromatographic method has been developed for the determination of morphine, morphine-3-glucuronide, morphine-6-glucuronide and codeine in plasma, urine and cerebrospinal fluid. The use of an efficient solid-phase extraction procedure together with a forward optical scanning detector allows a detection limit of 500 pg/ml. The method was evaluated by examination of biological samples taken from newborn infants following the intravenous administration of morphine sulfate.

Chromatography, High Pressure Liquid

Characteristics of endothelin binding sites in the spinal cord of spontaneously hypertensive rats.

The binding of [125I]sarafotoxin 6b (SRT 6b) and [125I]endothelin-1 (ET-1) to endothelin (ET) receptors of neuronal membranes prepared from cerebral cortex and spinal cord of 8-week-old spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY) was determined. SHR had significantly higher blood pressure as compared to WKY. Heart rate was similar in SHR and WKY. [125I]SRT 6b and [125I] ET-1 bound to the membranes of cerebral cortex and spinal cord at a single, high affinity site. The binding of [125I]SRT 6b and [125I]ET-1 in the cerebral cortex and spinal cord membranes was found to be similar in SHR and WKY. Concentration-dependent inhibition of [125I]ET-1 binding in spinal cord membranes by unlabeled ET-1, ET-2 and ET-3 was performed. The Ki values were found to be 2.35 +/- 0.68, 0.29 +/- 0.08 and 24.10 +/- 5.90 nM for ET-1, ET-2 and ET-3, respectively in WKY. The Ki values of ET-1 and ET-2 were found to be similar in WKY and SHR. However, the Ki value of ET-3 were found to be significantly lower (P less than 0.004) in SHR as compared to WKY. Concentration-dependent inhibition of [125I]SRT 6b binding in spinal cord membranes by unlabeled ET-1, ET-2 and ET-3 were also performed. The Ki values were found to be 9.50 +/- 2.10 pM, 0.17 +/- 0.04 nM and 31.20 +/- 6.00 nM for ET-1, ET-2 and ET-3, respectively in WKY. The Ki values of ET-1 and ET-2 were found to be similar in WKY and SHR.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Differences in the binding of [3H][D-Ser2,Thr6]leucine-enkephalin and [3H][D-Pen2,D-Pen5]enkephalin to brain membranes of morphine tolerant-dependent rats.

The effect of morphine tolerance-dependence and abstinence on the characteristics of delta-opiate receptors was determined in male Sprague-Dawley rats. Two ligands used for characterizing the receptors were [3H][D-Ser2,Thr6]leucine-enkephalin ([3H]DSTLE) and [3H][D-Pen2,D-Pen5]enkephalin ([3H]DPDPE). Rats were implanted s.c. under light ether anesthesia with six morphine pellets (each containing 75 mg of morphine free base). Rats which served as controls were implanted similarly with placebo pellets. Two sets of rats were used. In one group of rats, the pellets were left intact (tolerant-dependent) at the time of sacrificing and in the other the pellets had been removed 18 h earlier (abstinent). The spinal cord and brain regions (amygdala, hippocampus, hypothalamus, corpus striatum, mid-brain, pons and medulla and cortex) were dissected for binding studies. The binding of [3H]DSTLE to membranes of cerebral cortex of morphine-tolerant-dependent rats was decreased in comparison to control rats, and was due to a decrease in Bmax rather than Kd value. The binding of [3H]DSTLE to other brain regions or spinal cord of morphine-tolerant-dependent and abstinent rats did not differ from their respective controls. On the other hand, the binding of [3H]DPDPE was unaffected in any brain region or the spinal cord of morphine-tolerant-dependent and abstinent rats when compared to their controls. The decrease in binding of [3H]DSTLE to cortical membranes of morphine-tolerant-dependent rats amounted to 15%. Since DSTLE also binds to mu-opiate receptors, which have earlier been shown to be decreased in cortex of morphine-tolerant-dependent rats, and the binding of a more selective delta-opiate ligand [3H]DPDPE was unaffected, it is concluded that central delta-opiate receptors do not play a role in the development of morphine-induced tolerance-dependence or abstinence processes in the rat.

Analgesics

Spinal transection reduces both spinal antinociception and CNS concentration of systemically administered morphine in rats.

Within one day after spinal transection, the antinociceptive effect of systemically administered morphine on the spinal withdrawal reflex is significantly reduced. This observation has provided important empirical support for the present model of opiate-induced analgesia. One prediction from this model is that the antinociceptive effect of intrathecal (spinal) morphine injections should not be reduced by spinalization. When examined experimentally, this prediction was not supported; the antinociceptive effect of intrathecally administered morphine was significantly enhanced after acute spinalization. This result suggested an alternate hypothesis of morphine-induced analgesia. One prediction from this new hypothesis is that the decreased behavioral response to systemic morphine in spinal rats is due to a decrease in the spinal concentration of morphine produced by spinal transection. To test this prediction separate groups of intact rats and acute (one day) spinal rats, were assessed with the tail-flick (TF) procedure 60 min after subcutaneous injection of various doses of morphine (0.75, 1.5, 3.0, 4.5, 6.0 or 9.0 mg/kg) or at different time points (30, 60, 90, 150 or 240 min) after a single injection of 9.0 mg/kg. Immediately after behavioral testing, the rats were killed and brains, spinal cords and blood samples were collected and subsequently analyzed with a morphine radioimmunoassay. The results show that the concentration of morphine in the brain and spinal cords of acute spinal rats is significantly lower than that of intact rats, whereas morphine levels in the blood do not differ. These data suggest that the decreased antinociceptive effect of subcutaneous morphine in acute rats is due to a decrease in the concentration of the opiate in the central nervous system.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Down-regulation of brain and spinal cord K-opiate receptors in spontaneously hypertensive, Wistar-Kyoto normotensive, and Sprague-Dawley rats by chronic treatment with U-50, 488H.

The effects of chronic administration of U-50,488H, a K-opiate receptor agonist, on the binding of [3H]ethylketocyclazocine ([3H]EKC) to K-opiate receptors on the cerebral cortical and spinal cord membranes of spontaneously hypertensive (SHR), Wistar-Kyoto normotensive (WKY), and Sprague-Dawley (SD) rats were determined. Age-matched (10 weeks old) male rats of each strain were injected twice daily for 7 days with either U-50,488H (25 mg/kg, i.p.) or its vehicle. On day 8, the rats were killed. The cerebral cortex and the spinal cord were isolated for binding studies. The systolic blood pressure and heart rate of SD and WKY rats did not differ but the blood pressure of SHR rats were higher than that of SD and WKY rats. The receptor density (Bmax) and apparent dissociation constant (Kd) values of [3H]EKC binding to the spinal cord of WKY and SHR rats did not differ. However, the spinal cord of SD rats had higher Bmax and Kd values than WKY or SHR rats. The cortex of the SD rats had a lower Bmax value than the other two strains. Treatment with U-50,488H decreased the Bmax value of [3H]EKC in spinal cord of SD rats, increased the Kd value in SHR rats, and had no effect in WKY rats. Decreases in the Bmax value were produced in the cortex of all strains of rats, but a greater effect was observed in WKY and SHR rats than in SD rats.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh

Down-regulation of alpha 2 adrenoceptors in ventrolateral medulla of spontaneously hypertensive rats.

The binding of [3H]idazoxan [correction of idaxazon] to imidazole sites and [3H]rauwolscine to alpha 2 adrenoceptors of neuronal membranes prepared from cerebral cortex and ventrolateral medulla of 10 week old spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats was determined. [3H]idazoxan [correction of idaxazon] bound to the membranes of cerebral cortex and ventrolateral medulla at a single high affinity site. The binding of [3H]idazoxan [correction of idaxazon] in ventrolateral medulla and cerebral cortex was found to be similar in SHR and WKY rats. [3H]Rauwolscine bound to the membranes of cerebral cortex and ventrolateral medulla at a single high affinity site. The binding of [3H]rauwolscine in the cerebral cortex was found to be similar in SHR and WKY rats. However, in the ventrolateral medulla [3H]rauwolscine binding was found to be significantly lower in SHR as compared to WKY rats. The decreased binding was due a decrease (32%) in the Bmax value in SHR rats as compared to WKY rats. The Kd values were similar in SHR and WKY rats. It is concluded that imidazole binding sites are not affected while, alpha 2 adrenergic binding sites are decreased in the ventrolateral medulla of SHR rats and may be contributing to the regulation of blood pressure.

Animals

Down-regulation of endothelin receptors in the ventrolateral medulla of spontaneously hypertensive rats.

The binding of [125I] sarafotoxin 6b (SRT 6b) and [125I] endothelin-1 (ET-1) to endothelin (ET) receptors of neuronal membranes prepared from cerebral cortex and ventrolateral medulla of 8 week old spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats was determined. [125I] SRT 6b bound to the membranes of cerebral cortex and ventrolateral medulla at a single high affinity site. The binding of [125I] SRT 6b in the cerebral cortex was found to be similar in SHR and WKY rats. However, in the ventrolateral medulla [125I] SRT 6b binding was found to be significantly lower in SHR as compared to WKY rats. The decreased binding was due to decrease (48%) in the Bmax values in SHR rats as compared to WKY rats. The Kd values were similar in SHR and WKY rats. [125I] ET-1 also bound to the membranes of cerebral cortex and ventrolateral medulla at a single high affinity site. The binding of [125I] ET-1 in the cerebral cortex was found to be similar in SHR and WKY rats. However, in the ventrolateral medulla [125I] ET-1 binding was found to be significantly lower in SHR as compared to WKY rats. The decreased binding was due to 36% decrease in the Bmax values in SHR rats as compared to WKY rats. The Kd values were similar in SHR and WKY rats. It is concluded that the population of ET receptors is less in the ventrolateral medulla of SHR rats and may be contributing to the regulation of blood pressure.

Animals

Opiate antagonist binding sites in discrete brain regions of spontaneously hypertensive and normotensive Wistar-Kyoto rats.

The binding of 3H-naltrexone, an opiate receptor antagonist, to membranes of discrete brain regions and spinal cord of 10 week old spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats was determined. The brain regions examined were hypothalamus, amygdala, hippocampus, corpus striatum, pons and medulla, midbrain and cortex. 3H-Naltrexone bound to membranes of brain regions and spinal cord at a single high affinity site with an apparent dissociation constant value of 3 nM. The highest density of 3H-naltrexone binding sites were in hippocampus and lowest in the cerebral cortex. The receptor density (Bmax value) and apparent dissociation constant (Kd value) values of 3H-naltrexone to bind to opiate receptors on the membranes of amygdala, hippocampus, corpus striatum, pons and medulla, midbrain, cortex and spinal cord of WKY and SHR rats did not differ. The Bmax value of 3H-naltrexone binding to membranes of hypothalamus of SHR rats was 518% higher than WKY rats but the Kd values in the two strains did not differ. It is concluded that SHR rats have higher density of opiate receptors labeled with 3H-naltrexone in the hypothalamus only, in comparison with WKY rats, and that such a difference in the density of opiate receptors may be related to the elevated blood pressure in SHR rats.

Animals

Binding characteristics of [3H]SCH 23390 in spinal cord and discrete brain regions of kappa-opiate tolerant-dependent and abstinent rats.

The effects of chronic administration of U-50,488H, a highly selective kappa-opiate receptor agonist, and its subsequent withdrawal were determined. The binding characteristics of [3H]SCH 23390 to dopamine D1 receptors were investigated on membranes of rat spinal cord and in discrete brain regions. Male Sprague-Dawley rats received U-50,488H (25 mg/kg) intraperitoneally twice a day for 4 days. Animals serving as controls received only vehicle. Two different treatment schedules were used. In one, rats were injected with U-40,588H on day 5 and were sacrificed 1 h later (tolerant-dependent rats). In another, the rats were sacrificed 16 h after the last injection of U-50,488H (abstinent rats). Chronic administration of U-50,488H resulted in the development of tolerance to its analgesic effect, as demonstrated by the decreased response to a challenge dose of U-50,488H compared to vehicle-injected rats. The binding characteristics (Bmax and Kd values) of [3H]SCH 23390 were unaffected in spinal cord and other regions of brain of tolerant-dependent rats. In U-50,488H-abstinent rats, Bmax values of [3H]SCH 23390 were increased in hypothalamic and striatal membranes, but Kd values were unaffected. These results suggest that, in U-50,488H-abstinent rats, dopamine D1 receptors are up-regulated in hypothalamus and striatum.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh

Differential effects of two kappa-opiate agonists, U-50,488H and U-69,593, on the binding of 3H-(3-MeHis2) thyrotropin-releasing hormone to rat spinal cord and amygdala membranes.

The effect of delta- and kappa-opiate receptor agonists on the binding of 3H-(3-MeHis2) thyrotropin-releasing hormone (3H-MeTRH) to membranes of the spinal cord and amygdala of male Sprague-Dawley rats was determined in an effort to further understand interactions between opiates and TRH receptors. The agonists used were D-Ala2-MePhe4-Gly-ol5-enkephalin (DAMGO, mu-receptor), cyclic D-penicillamine2-D-penicillamine5-enkephalin (DPDPE, delta-receptor), cyclic D-penicillamine2-L-penicillamine5-enkephalin (DPLPE, delta-receptor), D-Ala2-D-Leu5-enkephalin (delta-receptor), U-50,488H and U-69,593 (kappa-receptor). 3H-MeTRH bound to amygdala and spinal cord membranes at a single site with Bmax values of 35.7 +/- 5.4 and 15.8 +/- 2.6 fmol/mg protein, and Kd values of 6.3 +/- 1.1 and 5.2 +/- 0.7 nmol/l, respectively. The competition experiments were carried out at a concentration of 2 nmol/l 3H-MeTRH. The concentration of opiate ranged from 10(-9) to 10(-4) mol/l. DAMGO, DPDPE and DPLPE had no effect on the binding of 3H-MeTRH to amygdala or spinal cord membranes. The two highly selective kappa-agonists differed in their interaction with TRH receptors. Whereas U-69,593 did not modify the binding of 3H-MeTRH, U-50,488H significantly inhibited the binding of 3H-MeTRH to both spinal cord and amygdala membranes. U-50,488H has been found to be 10 times more potent than U-69,593 at the central kappa-opiate receptors and may explain their differential action at the TRH receptors. It is concluded that mu- and delta-opiate agonists do not interact with brain and spinal cord TRH receptors.(ABSTRACT TRUNCATED AT 250 WORDS)

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh

Analgesic and hyperthermic effects of intravenously administered morphine in the rat are related to its serum levels.

The analgesic response, colonic temperature changes and the pharmacokinetic parameters of i.v. administered morphine sulfate (2.5, 5.0 and 10.0 mg/kg) through indwelling cannulas in the jugular vein were determined in male Sprague-Dawley rats. The analgesic and hyperthermic responses were determined before and at 30-min intervals for a period of 360 min after the morphine injection and were expressed as area under the time-response curve. Blood samples were collected periodically for a period of 24 h. Serum was separated and was used for the estimation of morphine by the highly sensitive radioimmunoassay. The pharmacokinetic parameters, half life, the terminal elimination rate constant, the mean residence time, the apparent volume of distribution at steady state and the total clearance were determined by using noncompartmental analysis. The area under the serum concentration-time curve from time zero to infinity was related to the dose of morphine. The other parameters were the same for all the doses of morphine, except the serum levels of morphine extrapolated to zero time which increase gradually with the dose. Dose-dependent analgesic and hyperthermic responses were related to the area under the serum concentration-time curve. It is concluded that the dose-dependent pharmacological effects of morphine were related to the area under the serum concentration-time curve from time zero to infinity for serum levels of morphine but not to the other pharmacokinetic parameters.

Analgesia

Inter-relationship between dental, skeletal and chronological ages in well-nourished and mal-nourished children.

Dental casts, wrist roentgenograms and full mouth radiographs of teeth of 80 mal-nourished and 40 well-nourished children were evaluated and compared for correlation of dental, skeletal and chronological ages. The findings revealed (1) very high correlation between dental and skeletal ages (r = 0.9584); (2) high correlation of chronological age with dental and skeletal ages (r = 0.8635 and r = 0.8716); (3) out of all the three correlations considered, dental and skeletal ages had the maximum correlation; (4) malnutrition had a significant adverse effect on the skeletal and dental ages. Greater the severity of malnutrition, more pronounced was its effect on the dental and skeletal ages; and (5) no evidence of severity of malocclusion with retarded skeletal and dental ages.

Adolescent