The Maryland Racing Commission initiated steps yesterday to revamp the rules regarding Lasix use at state racetracks.

In a meeting that lasted more than seven hours at Laurel Race Course, the commission also unanimously overturned the stewards in a disqualification at Laurel; suspended trainer Steward Mitchell 30 days; validated Peter Brant's license to race horses in Maryland following his recent legal problems, and heard a petition from the Maryland Standardbred Horsemen's Association. The MSHA, formed earlier this year, is trying to challenge the Cloverleaf Standardbred Owners' Association as the recognized representative for owners, drivers and trainers within the state.

After months of discussion with members of Maryland's racing community and industry leaders of other states, the racing commission's medication committee presented several recommendations yesterday that could change the state's parameters regarding Lasix, a medication used to control respiratory bleeding in horses. Commission members said prospective requirements would not necessarily be uniform with those of other states.

The committee proposed that horses in Maryland be eligible to race with Lasix a year earlier, beginning at age 2, and that dosages be restricted to between 2 and 10 ccs in most instances. The medication period would be expanded to cover about four hours from time of administration to postrace test.

Commission members also said they would like to eventually eliminate the Lasix barn, where all horses using it currently receive the medication under state supervision.

In their first formal appearance before the commission, MSHA directors said the needs of Maryland's harness horsemen are not adequately served by Cloverleaf, a Delaware-based organization that has represented them for more than 20 years.

The commission left open the possibility that a vote be taken among licensees of Rosecroft and Delmarva Downs to determine which horsemen's group should represent them. Alan Foreman, a lawyer for Cloverleaf, questioned the extent of support for the MSHA and asked that horsemen disassociate themselves from Cloverleaf before a vote is taken.

In reversing the stewards, the commission ruled, 5-0, that Tacoboy was unjustly disqualified from fourth place in a race Oct. 6..

The commission suspended Mitchell 30 days after the veteran trainer had a third horse fail a postrace drug test this year.

Brant, a well-known thoroughbred owner and breeder, was cleared to run horses in Maryland after pleading guilty in federal court to failure to maintain records.