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Raj R, Mahey R, Bhatla N, Manchanda S, Kumari A, Ranjan R. Laparoscopic Inguinal Gonadectomy in a Case of Partial Androgen Insensitivity Syndrome and Bilateral Gonads in Inguinal Canal. J Minim Invasive Gynecol 2022. [DOI: 10.1016/j.jmig.2022.09.198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Kachhawa G, Mahey R, Varun N, Kamalakar D, Rakhi R, Sharma J, Bhatla N. 8697 Vaginoplasty in MRKH: A Single Center Experience. J Minim Invasive Gynecol 2022. [DOI: 10.1016/j.jmig.2022.09.460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Mahey R, Cheluvaraju R, Kachhawa G, Singh S, Bhatla N. 8995 Laparoscopic Hernia Repair in a Patient with Mayer-Rokitansky-Kuster-Hauser Syndrome, Turner Mosaic Syndrome and Tubo-Ovarian Hernia. J Minim Invasive Gynecol 2022. [DOI: 10.1016/j.jmig.2022.09.527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Cheluvaraju R, Mahey R, Kumari A, Bhatla N. 8974 Laparoscopic Loop and Stitch Technique in Tubal Stump Ectopic Pregnancy. J Minim Invasive Gynecol 2022. [DOI: 10.1016/j.jmig.2022.09.521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Kashyap A, Singh N, Malhotra N, Mahey R, Perumal V, Vatsa R, Patel G, Saini M. O-292 Comparison of effect of two different trigger regimens; single (hCG) versus dual (hCG + Leuprolide) on outcome of fresh IVF cycles: A randomized controlled trial. Hum Reprod 2022. [PMCID: PMC9384440 DOI: 10.1093/humrep/deac106.085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Study question
Does adding gonadotropin-releasing hormone agonist (GnRHa) to hCG trigger increases the number of high-grade embryos in GnRH antagonist protocol in fresh non-donor IVF?
Summary answer
Final oocyte maturation triggered by dual trigger increases the number of MII oocytes thus transferring good-quality embryos and cryopreserving surplus embryos compared to hCG trigger.
What is known already
hCG has been conventionally used as a ‘faux’ LH surge to bring about final oocyte maturation due to structural similarity between the two. GnRH agonist, on the other hand, induces a more physiological gonadotropin surge for follicular maturation, but is associated with luteal phase deficiency. Recent studies have shown that combining GnRHa with hCG trigger improves oocyte maturation and embryo quality with the added benefit of a luteal phase support, thereby improving IVF outcomes in terms of both embryological and reproductive outcomes.
Study design, size, duration
A single-center, open labelled, randomized controlled trial including 100 normal responder patients between 21-38 years undergoing IVF using GnRH antagonist protocol between January 2020 to August 2021. The study excluded patients with the presence of other variables of adverse outcomes like diminished ovarian reserve (AFC < 5 or AMH < 1.2 ng/ml), endocrine disorders, thin endometrium (<6mm), previous history of uterine surgeries, and high responders.
Participants/materials, setting, methods
100 patients undergoing fresh IVF cycle using GnRH antagonist protocol were randomized after informed consent to receive either dual trigger (Leuprolide acetate 1 mg + rhCG 250 mcg, n = 50) or single hCG trigger (rhCG 250 mcg, n = 50). Oocyte retrieval was done 35-37 hours after trigger followed by IVF/ICSI, as indicated. Oocyte and embryo grading was done using Istanbul consensus. Analysis was done by ITT. Outcomes were analyzed using Independent t-test and Chi-square test.
Main results and the role of chance
The baseline characteristics were comparable in both arms. the number of MII oocytes retrieved (7.82 versus 5.92, p = 0.003) and the number of day-3 grade-1 embryos (4.24 versus 1.8, p < 0.001) were higher in the dual trigger group, whereas fertilization rates between the two groups (91.82% versus 88.51%, p=NS) were comparable. Consequently, the number of embryos cryopreserved (2.68 versus 0.94, p < 0.001) were significantly higher in the dual trigger group. However, the implantation rate between the two groups (21% versus 19.6%, p = 0.770) was comparable. The serum LH levels 12 hours post trigger were measured in both the arms and as expected, high serum LH values were documented in the dual trigger group (46.23 mIU/ml vs 0.93 mIU/ml, p < 0.0001).
Limitations, reasons for caution
Due to the impact of the Covid-19 pandemic causing an intermittent pause in IVF services at our center, a smaller sample size of 100 patients could be enrolled in the study, and reproductive outcomes in terms of live births and cumulative live births could not be assessed
Wider implications of the findings
This study, though small, has contributed to some evidence of redesigning the dual trigger in all antagonist cycles, with the exception of high responders and PCOS patients. The addition of GnRHa to hCG trigger has led to the possibility of cryopreserving surplus embryos thereby increasing the cumulative live births.
Trial registration number
CTRI/2020/08/027030
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Affiliation(s)
- A Kashyap
- India Institute Of Medical Sciences- New Delhi, Department of Obstetrics and Gynaecology All , New Delhi, India
| | - N Singh
- India Institute Of Medical Sciences- New Delhi, Department of Obstetrics and Gynaecology All , New Delhi, India
| | - N Malhotra
- India Institute Of Medical Sciences- New Delhi, Department of Obstetrics and Gynaecology All , New Delhi, India
| | - R Mahey
- India Institute Of Medical Sciences- New Delhi, Department of Obstetrics and Gynaecology All , New Delhi, India
| | - V Perumal
- India Institute Of Medical Sciences- New Delhi, Department of Obstetrics and Gynaecology All , New Delhi, India
| | - R Vatsa
- India Institute Of Medical Sciences- New Delhi, Department of Obstetrics and Gynaecology All , New Delhi, India
| | - G Patel
- India Institute Of Medical Sciences- New Delhi, Department of Obstetrics and Gynaecology All , New Delhi, India
| | - M Saini
- India Institute Of Medical Sciences- New Delhi, Department of Obstetrics and Gynaecology All , New Delhi, India
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Patel G, Singh N, Malhotra N, Mahey R, Saini M, Sethi A. P-799 To evaluate the effect of Intra-ovarian platelet rich plasma instillation on the clinical outcome of women with diminished ovarian reserve: A prospective interventional study. Hum Reprod 2022. [DOI: 10.1093/humrep/deac107.734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Study question
Does intra-ovarian instillation of platelet rich plasma (PRP) improves the clinical outcome of IVF cycles in women with Diminished Ovarian reserve (DOR)?
Summary answer
PRP instillation leads to consistent improvement in Antral follicle count (AFC), thus achieving clinical pregnancy rate of 33.3% per cycle in women with DOR.
What is known already
There is rising incidence of females with diminished ovarian reserve (DOR) especially among Asian ethnicity. With the emergence of regenerative medicine, multiple studies have evaluated the role of intra-ovarian PRP, demonstrating a beneficial role in improving ovarian reserve parameters (serum Follicular stimulating hormone (FSH), serum anti-Mullerian hormone (AMH), AFC). Despite its’ favorable effects on biochemical markers and AFC, data regarding improvement in clinical outcome remains elusive and led to inception of this study.
Study design, size, duration
A prospective interventional study was conducted at Division of Reproductive Medicine of a tertiary care institute. 41 infertile females aged 20-39 years with DOR (AMH <1.2 ng /ml; AFC<5) were enrolled in the study during a 6-month period beginning from August 2021.
Participants/materials, setting, methods
After informed consent, patients received fresh autologous PRP, prepared from 30 ml venous blood. 1.5ml of PRP instilled in each ovarian stroma between day 7-10 of menstrual cycle under sedation. Patients were followed up for three-consecutive months to assess ovarian reserve parameters including serum FSH, AMH and AFC. Patients showing significant improvement in parameters were recruited for fresh IVF cycles using Antagonist protocol with 1% transdermal testosterone. Outcomes were analysed using linear mix effect model.
Main results and the role of chance
The average platelet concentration in PRP was ∼10,00,000 platelets/µL. The mean age of enrolled patients was 31.22±4.16 years. Linear improvement in AFC (3.63 vs 6.98 vs 7.97 vs 6.90, p<0.001) was observed from baseline to three consecutive follow-up months with maximal response witnessed in second month in 57.1% of those undergoing IVF cycle. However, there was no significant difference in Serum FSH (p=0.11) and AMH (p=0.16) from the baseline post intervention. Of the 41 patients, 35 (85.3%) responded to the treatment and underwent IVF antagonist cycle. 5 out of 35 IVF cycles were cancelled mid-cycle due to poor ovarian response. The mean dose of gonadotropin requirement was 2667.5±281.1 IU (Follicular stimulating hormone) and 1400±337.3 IU (Human menopausal gonadotropin). The average number of oocytes retrieved was 5.7±2.2 whereas mean number of MII oocytes was 4.63±1.85. The fertilization rate and the cleavage rate were 92.4% and 74.1% respectively. Of the thirty patients, eight patients underwent day 2 transfer due to poor grade of embryos. Mean number of grade 1- day 3 embryos was 1.25±0.55 with surplus embryos available for cryopreservation in 14 patients. The overall clinical pregnancy rate per transfer was 33.33%. No adverse events were reported.
Limitations, reasons for caution
This was a prospective single arm study. A randomized controlled trial comprising a “no-treatment” arm would establish a Level-I evidence. However, “no-treatment” arm in a developing country like ours, imposes financial burden on the couple with no guaranteed clinical success and thus raising ethical concern and need for ovarian rejuvenation.
Wider implications of the findings
With the impetus to provide a biological child to these DOR women, intra-ovarian PRP instillation as a method of ovarian rejuvenation holds promising results. Evidently, PRP is not only effective in improving ovarian reserve but this translates into an improved reproductive outcome in a population, previously limited to oocyte donation.
Trial registration number
REF/2022/01/051033
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Affiliation(s)
- G Patel
- All India Institute of Medical Sciences- New Delhi, Division of Reproductive Medicine- Department of Obstetrics and Gynaecology , New Delhi, India
| | - N Singh
- All India Institute of Medical Sciences- New Delhi, Division of Reproductive Medicine- Department of Obstetrics and Gynaecology , New Delhi, India
| | - N Malhotra
- All India Institute of Medical Sciences- New Delhi, Division of Reproductive Medicine- Department of Obstetrics and Gynaecology , New Delhi, India
| | - R Mahey
- All India Institute of Medical Sciences- New Delhi, Division of Reproductive Medicine- Department of Obstetrics and Gynaecology , New Delhi, India
| | - M Saini
- All India Institute of Medical Sciences- New Delhi, Division of Reproductive Medicine- Department of Obstetrics and Gynaecology , New Delhi, India
| | - A Sethi
- All India Institute of Medical Sciences- New Delhi, Division of Reproductive Medicine- Department of Obstetrics and Gynaecology , New Delhi, India
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Bhatla N, Mahey R, Gupta M, Anukriti K. Laparoscopic Inguinal Gonadectomy in a Case of Familial Complete Androgen Insensitivity Syndrome and Inguinal Mass. J Minim Invasive Gynecol 2020. [DOI: 10.1016/j.jmig.2020.08.360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Goel T, Sharma J, Mahey R, Kachhawa G, Kriplani I, Kriplani A. Effect of Anti Tubercular Treatment on Laparoscopic Obstetrics and gynecology department at a hospital and Hysteroscopic Findings in Infertile Women with Genital Tuberculosis. J Minim Invasive Gynecol 2018. [DOI: 10.1016/j.jmig.2018.09.695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Kriplani A, Mahey R, Kachhawa G, Karthik S, Kriplani I. Laparoscopic Peritoneal Vaginoplasty in Mayer Rokitansky Kuster Hauser Syndrome – An Experience at Tertiary Care Center. J Minim Invasive Gynecol 2017. [DOI: 10.1016/j.jmig.2017.08.520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Malhotra N, Dolkar D, Mahey R, Singh N. To flush or not to flush: a randomized controlled trial comparing follicular flushing and direct aspiration at oocyte retrieval in poor responders undergoing IVF. Fertil Steril 2017. [DOI: 10.1016/j.fertnstert.2017.07.715] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Mahey R, Goel T, Gupta M, Kachhawa G, Kriplani A. To evaluate the pregnancy rate after endometrial scratching in couples with unexplained infertility in ovulation induction and IUI cycles. Fertil Steril 2015. [DOI: 10.1016/j.fertnstert.2015.07.1068] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Kriplani A, Mahey R, Kachhawa G, Wangdi T, Badigar S, Sds K. Laparoscopic Myomectomy for Cervical Myoma – Tips and Tricks. J Minim Invasive Gynecol 2014. [DOI: 10.1016/j.jmig.2014.08.414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Singh N, Kriplani A, Mahey R, Kachhawa G. Management of narrow introitus with Fenton's operation followed by successful pregnancy in a woman with repaired bladder exstrophy. J OBSTET GYNAECOL 2014; 35:426. [PMID: 25188695 DOI: 10.3109/01443615.2014.954531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- N Singh
- Department of Obstetrics and Gynaecology, All India Institute of Medical Sciences , New Delhi , India
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Kriplani A, Wangdi T, Menon R, Mahey R, Kachhawa G. Laparoscopic Removal of Eroded Mesh Following Laparoscopic Sacrocolpopexy. J Minim Invasive Gynecol 2013. [DOI: 10.1016/j.jmig.2013.08.170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Kriplani A, Mahey R, Dash B, Kulshrestha V, Agarwal N, Bhatla N. M518 ROLE OF INTRAVENOUS IRON SUCROSE THERAPY IN MODERATE TO SEVERE ANAEMIA IN PREGNANCY. Int J Gynaecol Obstet 2012. [DOI: 10.1016/s0020-7292(12)61706-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Pahwa P, Khaitan BK, Rao A, Kriplani A, Mahey R, Subbarao KC. Aggressive angiomyxoma of the vulva in a patient with systemic lupus erythematosus. Indian J Dermatol Venereol Leprol 2012; 78:361-4. [PMID: 22565439 DOI: 10.4103/0378-6323.95457] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Aggressive angiomyxoma is a rare, slow-growing mesenchymal neoplasm with a tendency to recur. It mainly involves the pelvis, vulva, perineum, vagina, and urinary bladder in adult women of reproductive age group. We describe a 26-year-old female with large swellings of both labia majora which was histologically diagnosed as aggressive angiomyxoma. She also had systemic lupus erythematosus. The swelling was surgically removed and she had no recurrence at 1-year follow-up. Although it is a rare tumor, it must be considered as a differential diagnosis for any mass in the perineum or soft tissue of the pelvis. Long-term follow-up is necessary for early diagnosis of local recurrence.
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Affiliation(s)
- P Pahwa
- Department of Dermatology and Venereology, All India Institute of Medical Sciences, New Delhi, India
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Kriplani A, Mahey R, Agarwal N, Bhatla N. Laparoscopic Management of Juvenile Cystic Adenomyoma – A Rare Cause of Dysmenorrhea. J Minim Invasive Gynecol 2011. [DOI: 10.1016/j.jmig.2011.08.381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Mahey R, Kriplani A, Agarwal N, Dash B. Hysteroscopic Myomectomy in Patients of Submucous Myoma: A Prospective Study. J Minim Invasive Gynecol 2011. [DOI: 10.1016/j.jmig.2011.08.529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Mahey R, Agarwal N, Kriplani A, Saraya A, Garg P. P116 Role of serum bile acids in diagnosis of intrahepatic cholestasis of pregnancy and effect of ursodeoxycholic acid therapy on bile acids and perinatal outcome. Int J Gynaecol Obstet 2009. [DOI: 10.1016/s0020-7292(09)61607-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Dash B, Kriplani A, Agarwal N, Mahey R, Bhatla N. P95 Pregnancy in patients with non-cirrhotic portal hypertension. Int J Gynaecol Obstet 2009. [DOI: 10.1016/s0020-7292(09)61586-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Abstract
Three adenylyl cyclases (ACI, ACIII, and ACVIII) have been described, which are putatively Ca(2+)-stimulable, based on in vitro assays. However, it is not clear that these enzymes can be regulated by physiological rises in [Ca2+]i when expressed in intact cells. Furthermore, it is not known whether transfected adenylyl cyclases might display the strict requirement for capacitative Ca2+ entry that is shown by the Ca(2+)-inhibitable ACVI, which is indigenous to C6-2B glioma cells (Chiono, M., Mahey, R., Tate, G., and Cooper, D. M. F. (1995) J. Biol. Chem. 270, 1149-1155). In the present study, ACI, ACIII, and ACVIII were heterologously expressed in HEK 293 cells, and conditions were devised that distinguished capacitative Ca2+ entry from both internal release and nonspecific elevation in [Ca2+]i around the plasma membrane. Remarkably, not only were ACI and ACVIII largely insensitive to Ca2+ release from stores, but they were robustly stimulated only by capacitative Ca2+ entry and not al all by a substantial increase in [Ca2+]i at the plasma membrane elicited by ionophore. (ACIII, reflecting its feeble in vitro sensitivity to Ca2+, was unaffected by any [Ca2+]i rise.) These results suggest a quite unsuspected, essential association of Ca(2+)-sensitive adenylyl cyclases with capacitative Ca2+ entry sites, even when expressed heterologously.
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Affiliation(s)
- K A Fagan
- Department of Pharmacology and Neuroscience Program, University of Colorado Health Sciences Center, Denver 80262, USA
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Chiono M, Mahey R, Tate G, Cooper DM. Capacitative Ca2+ entry exclusively inhibits cAMP synthesis in C6-2B glioma cells. Evidence that physiologically evoked Ca2+ entry regulates Ca(2+)-inhibitable adenylyl cyclase in non-excitable cells. J Biol Chem 1995; 270:1149-55. [PMID: 7836373 DOI: 10.1074/jbc.270.3.1149] [Citation(s) in RCA: 138] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Elevation of cytosolic free Ca2+ inhibits the type VI adenylyl cyclase that predominates in C6-2B cells. However, it is not known whether there is any selective requirement for Ca2+ entry or release for inhibition of cAMP accumulation to occur. In the present study, the effectiveness of intracellular Ca2+ release evoked by three independent methods (thapsigargin, ionomycin, and UTP) was compared with the capacitative Ca2+ entry that was triggered by these treatments. In each situation, only Ca2+ entry could inhibit cAMP accumulation (La3+ ions blocked the effect); Ca2+ release, which was substantial in some cases, was without effect. A moderate inhibition, as was elicited by a modest degree of Ca2+ entry, could be rendered substantial in the absence of phosphodiesterase inhibitors. Such conditions more closely mimic the physiological situation of normal cells. These results are particularly significant, in demonstrating not only that Ca2+ entry mediates the inhibitory effects of Ca2+ on cAMP accumulation, but also that diffuse elevations in [Ca2+]i are ineffective in modulating cAMP synthesis. This property suggests that, as with certain Ca(2+)-sensitive ion channels, Ca(2+)-sensitive adenylyl cyclases may be functionally colocalized with Ca2+ entry channels.
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Affiliation(s)
- M Chiono
- Department of Pharmacology, University of Colorado Health Sciences Center, Denver 80262
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Abstract
A number of the currently described adenylyl cyclase species can be regulated by Ca2+ in the submicromolar concentration range in in vitro assays. The regulatory significance of these observations hinges on whether a physiological elevation in intracellular Ca2+ can regulate these cyclase activities in intact cells. However, achieving a physiological elevation in cytosolic Ca2+ is complicated by the fact that hormonal increases in cytosolic Ca2+ can be accompanied by additional effects, such as liberation of beta gamma-subunits of G-proteins and activation of protein kinase C, which can have disparate type-specific effects on cyclase activities. Therefore we have devised a strategy based on capacitative Ca2+ entry to show that, when types I and VI adenylyl cyclase are expressed in human embryonic kidney 293 cells, they are stimulated and inhibited respectively by Ca2+ entry. Blockade of Ca2+ entry by La3+ ions blocks the effects of Ca2+ entry on cyclic AMP synthesis. These studies establish that adenylyl cyclases deemed to be sensitive to Ca2+ in in vitro assays can be regulated by physiological Ca2+ entry, and therefore, such cyclases are poised to respond to changes in intracellular Ca2+ in tissues in which they are expressed.
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Affiliation(s)
- D M Cooper
- Department of Pharmacology, University of Colorado Health Sciences Center, Denver 80262
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Abstract
The regulation of the guinea-pig pancreatic acinar plasma membrane Ca2+ pump by protein kinase A, protein kinase C and calmodulin was investigated. The results were compared with the effects of these regulators on the high affinity Ca(2+)-ATPase found in this membrane preparation. The catalytic subunit of cyclic AMP-dependent protein kinase stimulated Ca2+ transport 2-fold, but had no effect on Ca(2+)-dependent ATPase activity. Purified protein kinase C, the phorbol ester 12-O-tetradecanoyl phorbol-13-acetate and diacylglycerol derivative, 1-stearoyl-2-arachidonoyl-sn-glycerol, failed to stimulate the Ca(2+)-uptake but augmented the Ca(2+)-dependent ATPase activity. Exogenously added calmodulin failed to stimulate either activity. In addition, two antagonists of calmodulin activity, trifluoperazine and compound 48/80 produced a concentration-dependent inhibition of Ca(2+)-transport. These data suggest the presence of endogenous calmodulin within guinea-pig pancreatic acinar plasma membranes. Both calmodulin antagonists failed to influence the Ca(2+)-dependent ATPase activity. The ability of boiled extracts from guinea-pig pancreatic acinar plasma membranes to stimulate the Ca(2+)-ATPase activity in calmodulin-depleted erythrocyte plasma membranes confirmed the presence of endogenous calmodulin. Our results imply a role for calmodulin and cAMP-dependent protein kinase, but not protein kinase C, in the regulation of Ca2+ efflux from pancreatic acinar cells. These results also provide further evidence suggesting that the high affinity Ca(2+)-ATPase does not catalyze the plasma membrane Ca(2+)-transport activity observed in pancreatic acini.
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Affiliation(s)
- R Mahey
- Division of Pharmacology and Toxicology, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada
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Mahey R, Bridges MA, Katz S. Relationship between Ca(2+)-transport and ATP hydrolytic activities in guinea-pig pancreatic acinar plasma membranes. Mol Cell Biochem 1991; 105:137-47. [PMID: 1833623 DOI: 10.1007/bf00227753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Partially purified plasma membrane fractions were prepared from guinea-pig pancreatic acini. These membrane preparations were found to contain an ATP-dependent Ca(2+)-transporter as well as a heterogenous ATP-hydrolytic activity. The Ca(2+)-transporter showed high affinity for Ca2+ (KCa2+ = 0.04 +/- 0.01 microM), an apparent requirement for Mg2+ and high substrate specificity. The major component of ATPase activity could be stimulated by either Ca2+ or Mg2+ but showed a low affinity for these cations. At low concentrations, Mg2+ appeared to inhibit the Ca(2+)-dependent ATPase activity expressed by these membranes. However, in the presence of high Mg2+ concentration (0.5-1 mM), a high affinity Ca(2+)-dependent ATPase activity was observed (KCa2+ = 0.08 +/- 0.02 microM). The hydrolytic activity showed little specificity towards ATP. Neither the Ca(2+)-transport nor high affinity Ca(2+)-ATPase activity were stimulated by calmodulin. The results demonstrate, in addition to a low affinity Ca2+ (or Mg2+)-ATPase activity, the presence of both a high affinity Ca(2+)-pump and high affinity Ca(2+)-dependent ATPase. However, the high affinity Ca(2+)-ATPase activity does not appear to be the biochemical expression of the Ca(2+)-pump.
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Affiliation(s)
- R Mahey
- Division of Pharmacology and Toxicology, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada
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Abstract
ATPase activity in rat heart sarcoplasmic reticulum was stimulated in a concentration-dependent manner by both Ca2+ and Mg2+ in the complete absence of the other cation. Increasing concentrations of Mg2+ produced an apparent inhibition of the Ca2(+)-dependent ATP hydrolysis. CDTA (trans-1,2-diaminocyclo-hexane-N,N,N',N'-tetraacetate) had no effect on these responses. The results indicate the presence of a low affinity non-specific divalent cation-stimulated ATPase in rat heart sarcoplasmic reticulum. However, sarcoplasmic reticulum vesicles transported Ca2+ with a high affinity (K0.5 Ca2+ = 0.41 microM) suggesting the presence of a high affinity Ca2(+)-transporting ATPase. Calmodulin did not stimulate rat heart sarcoplasmic reticulum ATPase activity over a range of Ca2+ and Mg2+ concentrations and failed to stimulate membrane phosphorylation and Ca2+ transport into sarcoplasmic reticulum vesicles. Calmodulin antagonists trifluoperazine and compound 48/80 did not affect the ATPase activity. Catalytic subunit of cAMP-dependent protein kinase was also ineffective in stimulating the ATPase activity. These results suggest the presence of an ATPase activity in rat heart sarcoplasmic reticulum with different properties from the high affinity Ca2(+)-pumping ATPase previously characterized in dog heart and other species.
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Affiliation(s)
- R Mahey
- Division of Pharmacology and Toxicology, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada
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Bridges M, Mahey R, Lau W, Hampong M, Katz S. Purification of Ca2+-ATPase from rat pancreatic acinar plasma membranes using calmodulin-affinity chromatography. Adv Exp Med Biol 1988; 232:83-5. [PMID: 2975146 DOI: 10.1007/978-1-4757-0007-7_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- M Bridges
- Division of Pharmacology and Toxicology, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada
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