Effects of corticosterone and its synthesis blockade on the cocaine-induced discriminative stimulus effects in rats

Several studies have argued that the hypothalamo-pituitary-adrenal (HPA) axis is of significance to behavioral effects evoked by drugs of abuse (e.g. cocaine). The role of the HPA axis in the subjective effects of cocaine was investigated in rats trained to discriminate cocaine (10 mg/kg, ip, -15 min) from saline (ip, -15 min) in a two-choice, water-reinforced fixed ratio (FR) 20 drug discrimination paradigm. In substitution tests, neither the exposure to a novel environment nor the social defeat stress, applied to rats after a dose of cocaine (2.5 mg/kg) which induced a ca. 42% drug-appropriate responding, influenced cocaine discrimination. Given alone, corticosterone (20 and 40 mg/kg, sc, -60 min) elicited a ca. 7% drug-appropriate responding. Combined injections of corticosterone and cocaine (0.625-5 mg/kg) did not affect the dose-response curve for cocaine. Surgical adrenalectomy did not modify the effects of cocaine; using a cumulative dosing procedure in the drug discrimination paradigm we found, that the dose-response curves for cocaine in adrenalectomized rats and sham-operated controls practically did not differ. Ketoconazole (an inhibitor of adrenocorticosteroid synthesis; 50 mg/kg, ip) given acutely (60 min) did not affect cocaine discrimination. Given subacutely (24, 16 and 1 h before tests), ketoconazole (50 mg/kg) produced a left-ward shift in the dose-response curve for cocaine and decreased its ED50 value. Another inhibitor of corticosterone secretion, metyrapone (50 mg/kg, sc), given acutely (120 min) did not affect the dose-response curve for cocaine. However, repeated injections (24, 16 and 2 h before tests) of metyrapone (50 mg/kg) with different doses of cocaine resulted in a rightward shift in the dose-response curve for cocaine and an increase in its ED50 value. The obtained results seem to exclude any role of the HPA axis in mediating subjective effects of cocaine, since neither corticosterone and stress nor adrenalectomy modified the discriminative stimulus effects of cocaine in rats. The reduction and potentiation of cocaine discrimination following subacute metyrapone and ketoconazole, respectively, may depend on changes in the levels of intermediate neurosteroids "upstream" from corticosterone in its biosynthesis pathway.

[The vitreoretinal complications of cataract surgery]

The paper reports a retrospective study performed between January 1996 and January 1999 which comprised 423 patients who underwent eye cataract surgery. Vitreoretinal complications (retinal detachment, cystoid macular edema, choroidal detachment, endophthalmitis, luxation of the lens into the vitreous body) were related to age, sex, other general and local diseases and surgical complications, like disruption of the posterior capsule. The study presents also vitreoretinal complications after Nd:YAG laser posterior capsulotomy. The outcomes of the study show that 18 cases (4.25%) had retinal detachment, 11 (2.60%) had cystoid macular edema, 2 cases had endophthalmitis, while choroidal detachment and luxation of the lens into the vitreous body were reported each in 1 case. Retinal detachment following Neodymium:YAG laser capsulotomy (performed in 109 cases) was found in 2 cases. All of those vitreoretinal complications were reported with a higher incidence in patients with vascular diseases (diabetes mellitus, arterial hypertension, angiosclerosis) and also in patients who had axial lengths of 25 mm or greater.

Dopamine D5 receptors in nucleus accumbens contribute to the detection of cocaine in rats

Dopamine D(1)/D(5) receptor antagonism has been shown to block the euphoric and stimulatory effects of cocaine in humans and rats. In the present study, rats trained to discriminate the presence of cocaine (10 mg/kg) from its absence were used to analyze the functional contribution of D(1) (D(1)R) versus D(5) (D(5)R) receptors in the nucleus accumbens, an important neural site for the actions of cocaine. Bilateral microinfusion into the nucleus accumbens of an antisense oligonucleotide directed at the D(5)R (0. 75 nmol/0.3 microl per side, two times per day for 3 d) elicited a downward shift in the dose-effect curve for cocaine with a suppression of peak efficacy; the dose of cocaine estimated to elicit 50% drug-lever responding (ED(50)) was 6.71 mg/kg when assessed 12 hr after the D(5)R antisense oligonucleotide compared to the control ED(50) of 1.83 mg/kg and to the ED(50) of 1.75 mg/kg established 7 d after the last D(5)R antisense oligonucleotide infusion. The D(1)R antisense and scrambled oligonucleotide (0.75 nmol/0.3 microl per side, two times per day for 3 d) were both ineffective. Thus, using drug discrimination techniques that model the subjective effects of cocaine, we show that responsiveness to cocaine is dramatically attenuated after interference with the process of translation of the D(5)R mRNA to its protein product. These findings suggest that D(5)R is a functionally important target site for the indirect actions of cocaine and that rigorous investigations of the function of D(5)R may help guide the discovery of strategies for pharmacotherapy in cocaine dependence.

Effect of adrenalectomy and corticosterone on cocaine-induced sensitization in rats

Effects of adrenalectomy (ADX) and corticosterone (CORT) on the development and expression of sensitization to the locomotor effect of cocaine (COC) were studied in rats. Sensitization was evoked by 5 daily injections of COC (10 mg/kg) and measured after a challenge dose of the drug (10 mg/kg) after a 5-day withdrawal (on day 10 of the experiment). ADX, performed before the start of COC administration, completely blocked the manifestation of COC-induced sensitization. In contrast, ADX performed on animals already sensitized to COC did not affect the sensitized locomotor activity response to a challenge dose of COC (on day 18). Pretreatment with CORT, 10 mg/kg, but not 5 mg/kg, before each of the 5 daily COC injections facilitated the development of COC sensitization, tested after a 5-day withdrawal. When pretreated with CORT alone (10 mg/kg), the challenge dose of COC administered on day 10 induced cross-sensitization to CORT. CORT (10 mg/kg) injected acutely before COC on day 10, potentiated the expression of COC sensitization. When given alone, on day 10 CORT (5-10 mg/kg) induced an increase in the locomotor activity of rats pretreated daily (5 injections) with COC. No drug treatment induced conditioned locomotion, as measured after saline challenge on day 8. Our results indicate that CORT facilitates the development and expression of COC sensitization, while ADX blocks the initiation of the behavioral phenomenon only. Moreover, there takes place cross-sensitization between CORT and COC, which indicates a close relationship between the drug-related mechanism and behavioral sensitization.

Activation of serotonin (5-HT)1A receptors inhibits amphetamine sensitization in mice

The effects of serotonin (5-HT)1A drugs on the development and expression of sensitization to the locomotor effect of amphetamine (AMPH) were studied in mice. 8-Hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), a 5-HT1A agonist, dose-dependently reduced the expression of AMPH (2.5 mg/kg)-induced sensitization. The latter inhibitory effect of 8-OH-DPAT was reversed by (S)-N-tert-butyl-3-(4-(2-methoxyphenyl)piperazin-1-yl)-2-phenyl propamine (WAY 100135), a 5-HT1A antagonist. WAY 100135 given alone did not affect expression of AMPH sensitization. Combined injections of 8-OH-DPAT, but not WAY 100135, with AMPH (2.5 mg/kg) during the development of sensitization, protected against the expression of sensitization to a challenge dose of AMPH (2.5 mg/kg) 3 days after withdrawal. The above inhibitory effect of 8-OH-DPAT on the development of AMPH sensitization was blocked by pretreatment with WAY 100135. The AMPH-induced conditioned locomotion was unaffected by pretreatment with 8-OH-DPAT. These results indicate that 5-HT1A receptors are not involved in AMPH-induced sensitization per-se, whereas their pharmacological activation leads to the inhibition of both the development and the expression of AMPH-induced sensitization.

Lack of effects of glycineB receptor ligands on the psychostimulant-induced discriminative stimuli in rats

To examine the role of glycineB receptors in the stimulus effects induced by psychostimulants, separate groups of rats were trained to discriminate amphetamine (AMPH; 1 mg/kg) from saline (SAL), or cocaine (COC; 10 mg/kg) from SAL, using a two-lever operant procedure. Substitution studies showed that neither 1-aminocyclopropanecarboxylic acid (ACPC; 200 mg/kg) nor 7-chloro-4-hydroxy-3-(3-phenoxy)phenyl-(H)quinolone (L-701,324; 3 mg/kg), being a partial agonist or an antagonist at glycineB receptors, respectively, generalized for the training drugs. Combination tests of glycineB ligands demonstrated that injection of a fixed dose of ACPC (200 mg/kg) or L-701,324 (3 mg/kg) together with different doses of AMPH or COC practically did not modify dose-response curves of the psychostimulants, nor did it affect their ED50 values. Our results indicate that glycineB receptors do not play a role in the discriminative effects of AMPH and COC.

[The tomographic diagnosis of Basedow's orbitopathy]

The inflammatory and infectious circumstances involving the orbit are known as 'orbitopathies' Considering the progress of immunology and imagistical investigations, it has been proposed a new classification of these entities. This classification divides the orbithopathies in specific and nonspecific. This paper brings up the case of a 65 year old female patient, showing unilateral proptosis with progressive evolution for about one year. The local examination and paraclinical investigations (computerised tomography and thyroid gland scintigram) sustained the diagnosis of Basedow disease. The ophthalmopathy in Basedow disease is a specific orbital involvement. Considering it's high rate of occurrence among the exophthalmic eyes (10%) it rests a severe disease, with a not yet fully understood physiopathology and a controversial treatment. The basedowian ophthalmopathy is, as well, an autoimmune disease, which requires the presence of T lymphocytes at the level of the orbital tissue. The computerised tomography gives us a direct visualisation of the enlarged muscles in hyperthyroidism (the muscles can increase 8 times their normal size), that is why we have to recommend it every time we are facing a patient with proptosis, especially unilateral.

Criteria for choosing lens implants

Choosing the proper artificial lens can be a problem, especially for the young surgeons, considering the fact that the "market" is so rich in possibilities. The present paper analyses the lens according to their dimension, form and material, in a perspective based on personal experience.

[Hydrophilic toric contact lenses in the correction of astigmatism]

Technological advances in the design and manufacture of soft toric contact lenses have made it possible for most astigmatic patients to achieve successful results with current soft lenses, but a small percentage of those patients are wearing them. We present the observations on 21 subjects that requested soft toric lenses in the past year. This lenses (TP 60) offered all the comfort of soft lenses and a good vision correction for astigmatism up to 6 diopters.

The role of the nitric oxide (NO) pathway in the discriminative stimuli of amphetamine and cocaine

To examine the role of the nitric oxide (NO) pathway in the stimulus effects induced by some psychostimulants, separate groups of rats were trained to discriminate between amphetamine (AMPH; 0.5 mg/kg) and saline, or cocaine (COC; 5 mg/kg) and saline using a standard two-lever operant procedure. Substitution studies showed that AMPH and COC generalized for the training drugs in a dose-dependent manner, their ED50, values being 0.1 mg/kg and 1.2 mg/kg, respectively. The dose-response function of both those psychostimulants did not change in the course of the experiment. Moreover, AMPH and COC induced cross-substitution effects towards each other. Successive combination tests demonstrated that injection of a fixed dose of the NO synthase (NOS) inhibitor 7-nitro indazole (7-NI; 25 mg/kg) plus different doses of AMPH or COC resulted in a leftward shift in the dose-response curves of those psychostimulants and a decrease in their ED50 values. On the other hand, pretreatment with the NO donor molsidomine (MOL), injected in a fixed dose of 100 mg/kg before AMPH and COC, shifted the dose-response curves of the psychostimulants to the right and increased their ED50 values. Our results indicate that NO plays an inhibitory role in the dopamine (DA)-evoked discrimination effects of AMPH and COC in rats.

Stimulation of serotonin (5-HT)1A receptors attenuates the locomotor, but not the discriminative, effects of amphetamine and cocaine in rats

The influence of serotonin (5-HT)1A receptor stimulation on the dopamine (DA)-mediated locomotor and discriminative behaviours was evaluated in rats. The increased locomotor activity induced by the indirect DA agonist amphetamine (0.5 mg/kg) or cocaine (5 mg/kg) was dose-dependently inhibited by 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT; 0.125-0.5 mg/kg), a 5-HT1A agonist. (S)-N-tert-butyl-3-[4-(2-methoxyphenyl)piperazin-1-yl]-2-phenylpro panamide (WAY 100135; 10 mg/kg), a selective 5-HT1A antagonist, did not change the hyperactivity induced by amphetamine or cocaine, but it reduced the inhibitory effect of 8-OH-DPAT on the hypermotility evoked by either psychostimulant. In drug discrimination experiments, 8-OH-DPAT (0.125-0.5 mg/kg) did not antagonize the stimulus effects of amphetamine (0.5 mg/kg) or cocaine (5 mg/kg). When given in combination with amphetamine (0.025-0.5 mg/kg) or cocaine (0.25-5 mg/kg), 8-OH-DPAT (0.5 mg/kg) did not modify the dose-response curves of those psychostimulants. The obtained results indicate that 8-OH-DPAT inhibits the amphetamine- or cocaine-induced increases in the locomotor activity in rats via stimulation of 5-HT1A receptors. On the other hand, the lack of the antidiscriminative effects of 8-OH-DPAT suggests that the two effects of amphetamine and cocaine are not modified in the same way by 5-HT1A receptors.

Nitric oxide (NO) pathway and locomotor hyperactivity towards dopaminomimetics in rats

The effects of the NO donor molsidomine and the inhibitors of the NO synthase (NOS) 7-nitroindazole (7-NI) and NG-nitro-L-arginine methyl ester (L-NAME) on the motor hyperactivity induced by indirect (amphetamine and cocaine) or direct (SKF 38393 and bromocriptine) dopamine (DA) agonists were studied in rats. The hyperactivity induced by 0.5 mg/kg of amphetamine or 5 mg/kg of cocaine was potentiated in a dose-dependent manner by molsidomine (30-100 mg/kg), but attenuated by 7-NI (3-30 mg/kg) or L-NAME (3-30 mg/kg). The NOS inhibitors also inhibited the locomotor hyperactivity evoked by 15 mg/kg of SKF 38393 (a DA D1 agonist) or 5 mg/kg of bromocriptine (a DA D2 agonist). On the other hand, the hyperactivity induced by those direct DA receptor agonists was potentiated by molsidomine. The present findings provide further evidence for an interaction at the behavioral level between NO and the DA-mediated effects of amphetamine and cocaine; moreover, they seem to indicate that both DA D1 and DA D2 receptor subtypes are under such influence.

The role of dopamine receptor subtypes in the discriminative stimulus effects of amphetamine and cocaine in rats

The role of dopamine (DA) receptor subtypes in the discriminative stimuli of the psychostimulant drugs of abuse amphetamine and cocaine was evaluated by the ability of DA D1, D2 and D3 receptor subtype ligands to either substitute for or antagonize these effects. Separate groups of rats were trained to discriminate between amphetamine (0.5 mg/kg) and saline, and between cocaine (5 mg/kg) and saline. Both the training drugs evoked cross-substitution. In further substitution experiments, (+)-2,3,4,5-tetrahydro-7,8-dihydroxy-1-phenyl-1H -3-benzazepine (SKF 38393; 5-20 mg/kg), a selective D1 agonist, moderately substituted for cocaine, but not for amphetamine. The D2 agonist bromocriptine (2.5-20 mg/kg) mimicked both training drugs' cues. Pramipexole, a D3-preferring agonist, in a dose of 0.5 mg/kg induced over 80% substitution for cocaine, and a weaker one (ca. 62%) for amphetamine. Combination tests with DA antagonists showed that the D1 antagonist (+)-3-methyl-7-chloro-8-hydroxy-1-phenyl-2,3,4,5-tetrahydro-1H -3-benzazepine (SCH 23390; 0.01-2 mg/kg), and the D2 blocker raclopride (0.13-1 mg/kg) significantly (78-100%) attenuated the effects of psychostimulants, while the D3-preferring antagonist cis-(+)-5-methoxy-1-methyl-2-(di-n-propylamino)tetralin (UH 232; 5-20 mg/kg) did not affect them. The present results indicate a critical role of D2 receptor subtypes in the discriminative stimuli of amphetamine and cocaine in rats, as well as a less pronounced involvement of D1 and D3 subtypes in the effects under study.

Effects of MP-3022 on the 8-OH-DPAT-induced discriminative stimulus in rats

To examine the effects of 4-[3-(benzotriazol-1-yl)-propyl]-1-(2-methoxyphenyl)piperazine (MP-3022), a high affinity 5-HT1A ligand, on the 5-HT1A-induced stimulus effect and to compare its effects with those produced by some 5-HT1A receptor ligands, rats were trained to discriminate between 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), 0.1 mg/kg ip, and saline in a standard, two-lever operant procedure. Substitution studies showed that the 8-OH-DPAT cue was mimicked in a dose-dependent manner by buspirone and ipsapirone, the 5-HT1A receptor partial agonists, but not by 1-(3-chlorophenyl)piperazine (m-CPP), a nonselective 5-HT agonist. Furthermore, the 8-OH-DPAT cue was almost completely blocked by 1-(2-methoxyphenyl)-4-[4-(2-phthalimido)]butylpiperazine (NAN-190), a 5-HT1A receptor and alpha 1-adrenoceptor antagonist, but not by prazosin (a selective alpha 1-adrenoceptor blocker). Our results also demonstrate that the discriminative effect of 8-OH-DPAT may be dose-dependently antagonized by MP-3022, which itself does not mimic the cue. It is concluded that MP-3022 behaves like a full 5-HT1A receptor antagonist in the 8-OH-DPAT-evoked discrimination procedure.

[Treatment of instability of the lumbar spine by glass-ceramic prostheses of the intervertebral disc.]

The authors evaluated the short-term results of stabilization operations of the lumbar spine by means of a glass-ceramics replacement of the intervertebral disc in a group of 25 patients. Indication for operation was monosegmental instability or spondylolisthesis grade I in the lumbar spine with progressing clinical symptoms. In 20 patients stabilization was achieved merely by a pair of glass-ceramic endoprostheses, in five patients the stabilization operation was supplemented by transpedicular instrumentation. Twenty-two patients, now 3-12 months after operation are better. In three patients the preoperative complaints persist, in one female patient due to a poorly performed operation and in two patients due to an incorrect surgical indication. Key words: instability of the lumbar spine, surgical stabilization of the lumbar spine by a glass-ceramic endoprosthesis.

Antioxidant action of a new flavonic derivative in acute carbon tetrachloride intoxication

The antioxidant potential of a new flavonic derivative named conventionally theophylline-rutoside [TR-1722] was estimated by the measurement of G-6-Pase activity (marker enzyme for the endoplasmic reticulum), catalase activity (enzyme involved in the antioxidant defence process), and total -SH groups from the hepatic homogenate, using CCl4 as a free radical generating model. To show changes in the permeability of the hepatocyte membrane, the activity of lactate dehydrogenase (LDH) in plasma was determined. The obtained results suggest that TR-1722 acts by curtailing both lipid peroxidation and alkylation processes.

MP-3022, a new putative antagonist at pre- and postsynaptic 5-HT1A receptors

The receptor binding and pharmacological profile of the new, putative 5-HT1A receptor antagonist MP-3022 (4-[3-(benzotriazol-1-yl)propyl]-1-(2-methoxyphenyl)piperazine) were studied. Another 5-HT1A receptor antagonist, (S)-WAY 100135 ((S)-N-tert-butyl-3-[4-(2-methoxyphenyl)piperazine-1-yl]-2- phenylpropanamide), was used as a reference drug in functional models. MP-3022 showed a high affinity (Ki) of 25 nM and 69 nM, respectively, at 5-HT1A binding sites and alpha 1-adrenoceptors in vitro. The Ki values of MP-3022 in relation to other binding sites examined (5-HT2A, alpha 2- or beta-adrenoceptors, dopamine D1 and D2) were 20-100-fold lower. In functional studies, MP-3022 significantly attenuated the 8-OH-DPAT (8-hydroxy-2-(di-n-propylamino)tetralin)-induced decrease in the population spike evoked in the CA1 cell layer of the hippocampal slice preparation, without producing its own effects. The 8-OH-DPAT-evoked increase in the corticosterone concentration in the serum as well as the 8-OH-DPAT-mediated decrease in the 5-HT turnover in the hippocampus were attenuated by MP-3022. MP-3022 increased the serum corticosterone concentration only at the highest dose used, but it did not change the 5-HT turnover in the hippocampus. Like MP-3022, (S)-WAY 100135 antagonized the 8-OH-DPAT-induced effects. It has also been demonstrated that (S)-WAY 100135 is devoid of an intrinsic activity at 5-HT1A receptors. The data obtained demonstrate that, like (S)-WAY 100135, MP-3022 behaves like a functional antagonist at pre- and postsynaptic 5-HT1A receptors.

[The use of prostaglandin compounds in treating glaucoma]

The theoretical part of this paper presents the mechanism of the IOP lowering effect using these drugs, the indications of treatment and the main side effects. The second part consist of the experimental study made on rabbits, using the izopropilic ester of (+)Cloprostenol as an hypotensive agent. We have registered the IOP values and the main side effect--conjunctival hyperemia. The third part consist of the clinical study, made on a test lot of 23 patients. We have used the same substance and in the experimental study, as a unique treatment or in association with a beta-blocker or a pilocarpine derivative. The following-up has implied: the IOP, the ophthalmoscopic appearance of the optic disc, the visual field, the visual acuity and the main side effects. In the end, we have formulated the conclusions of these studies.

[The differential diagnosis between symptomatic and idiopathic retinal detachments]

The paper presents a synthesis of today's means for differential diagnosis between symptomatic and idiopathic retinal detachment, considering that the retinal detachment remains an ocular emergency, with high invalidity potential. The characteristic difficulties of this diagnosis are also detailed. The different medical attendance of the two types of retinal detachment requires a rigorous differential diagnosis, according the leading part to the ophthalmological examination. There are also illustrated up-to-date diagnosis tests, less invasive and more informative, such as: CT and MRI. The survey highlights the value still relative of the majority of these investigations and the fundamental significance of the histological examination.

[The explantation and replacement of artificial lens implants]

The paper presents the statistical study of the appearance of explantation on the whole of artificial lenses implants, at the Ophthalmology Service of the Central Military Hospital during the years 1989-1993. The statistics relies on the review of data extracted from the operation registers, elaborated during the mentioned period, followed by their computerized processing and plotting. The authors also referred to the types of postoperative complications and their weight in the genesis of the explanation, as well as their distribution related to the sort of implanted intraocular lens. The survey also illustrates the long-run evolution of the reimplantation percentage. The results are comparatively reviewed to those in the specialty literature.

[Pneumatic retinopexy with SF6]

Pneumatic retinopexy has been recently reported as an alternative procedure in the treatment of retinal detachments. This technique may be considered if the break is no larger than the 1 o'clock hour, the break is located superiorly between 8 o'clock and 4 o'clock and there is no proliferative vitreoretinopathy greater than C1. The expandable gas SF6 (sulphur hexafluoride) has been used in the treatment of 16 cases of retinal detachment. Two of them were new cases treated with pneumatic retinopexy and cryotherapy applications and they were both successful. The other 14 cases were redetachments, so the treatment was completed by scleral buckling in 9 cases and scleral buckling with permanent implants of silicon in 5 cases. The rate of success was 3 to 9 and 2 to 5. For the rest of 9 cases vitrectomy or silicon oil injection would have been useful. Pneumatic retinopexy proved to be a low-price surgical treatment easy to use even in a consulting room, in one or two-session method. It may be performed as a single procedure for new cases of superior retinal detachments or in addition to other surgical techniques on selected cases.

[Replacement of an intervertebral disc, using a ceramic prosthesis, in the treatment of degenerative diseases of the spine.]

The authors tested in experimentally a suitable shape and approach to replacement of an intervertebral disc by means of an endoprosthesis made from glass-ceramic material of Lasak Co. In experiments on post-mortem material they succeded eventually in creating the optimal shape and finding a route of administration of the endoprosthesis into the intervertebral space. The endoprosthesis should create a spondylodesis and primary fixation of the affected portion of the lumbar spine. In some instances it thus will not be necessary, after insertion of the ceramic prosthesis into the intervertebral space, to make a supplementary instrumental fixation. Key words: ceramic endoprosthesis, replacement of degenerated lumbar intervertebral disc.

[Corneal transplantation today]

Corneal transplant become a surgical procedure which is performed with success in more many ophthalmological medico-surgical centers. This way it raised a fully experience concerning selection of cases and the preservation of the graft, surgical technique and the graft rejection. The authors present a general view of the problems concerning keratoplasty making a briefly summary of the indications, contraindications and prognosis of this technique, screening of donor tissue and a little larger one the surgical technique with his problems: trephining, preserving the donor tissue and placing the graft, and also the postoperative problems--suture removal, visual correction and corneal transplant rejection.

Structure-activity relationship studies of central nervous system agents. 13. 4-[3-(Benzotriazol-1-yl)propyl]-1-(2-methoxyphenyl)piperazine, a new putative 5-HT1A receptor antagonist, and its analogs

A new set of 4-alkyl-1-(o-methoxyphenyl)piperazines containing a terminal benzotriazole fragment were synthesized, and their 5-HT1A and 5-HT2 affinity was determined. It was shown that the benzotriazole moiety contributes to both the 5-HT1A and 5-HT2 receptor affinity. It was demonstrated in several behavioral models that 4-[3-(benzotriazol-1- yl)propyl]-1-(2-methoxyphenyl)piperazine (11) is a new, potent presynaptic and postsynaptic 5-HT1A receptor antagonist. However, it is not selective for 5-HT1A versus alpha 1 receptors.

The role of 5-hydroxytryptamine1A (5-HT1A) receptors in the anticonflict activity of beta-adrenoceptor antagonists

Using the conflict drinking test as a model, we studied in rats the effect of the nonselective beta-adrenoceptor blockers pindolol and cyanopindolol which bind to 5-HT1A and 5-HT1B receptors, and of the selective beta 1- and beta 2-adrenoceptor antagonists betaxolol and ICI 118,551, respectively, which have a negligible affinity for 5-HT receptors. Both pindolol (2.0-8.0 mg/kg) and cyanopindolol (0.5-2.0 mg/kg) showed an anticonflict effect, having dose dependently increased the number of punished licks. On the other hand, neither betaxolol nor ICI 118,551--administered separately or in combination--affected the punished responding. The anticonflict effects of pindolol and cyanopindolol were completely abolished by the 5-HT1A receptor and alpha 1-adrenoceptor antagonist 1-(2-methoxyphenyl)-4-[4-(2-phtalimmido)butyl]piperazine (NAN-190), but were not modified by the selective alpha 1(-)-adrenoceptor antagonist prazosin. The effects of pindolol and cyanopindolol were also not modified in animals with lesions of 5-HT neurons, produced by p-chloroamphetamine (PCA). Moreover, it was also found that the anticonflict effects of pindolol and cyanopindolol in PCA-pretreated rats were antagonized by NAN-190 but not prazosin. Our results indicate that the anticonflict effects of pindolol and cyanopindolol depend on their agonist action on postsynaptic 5-HT1A receptors.